diff --git a/Elwig/Helpers/Billing/Varibute.cs b/Elwig/Helpers/Billing/Varibute.cs
index 60cedb5..d89c662 100644
--- a/Elwig/Helpers/Billing/Varibute.cs
+++ b/Elwig/Helpers/Billing/Varibute.cs
@@ -62,8 +62,8 @@ namespace Elwig.Helpers.Billing {
 
         public Varibute(RawVaribute raw) :
             this(raw.SortId != null ? new WineVar(raw.SortId, raw.SortId) : null,
-                 raw.AttrId != null ? new WineAttr(raw.AttrId, raw.AttrId) : null,
-                 raw.CultId != null ? new WineCult(raw.CultId, raw.CultId) : null) {
+                 raw.AttrId != null ? new WineAttr() { AttrId = raw.AttrId, Name = raw.AttrId } : null,
+                 raw.CultId != null ? new WineCult() { CultId = raw.CultId, Name = raw.CultId } : null) {
         }
 
         public Varibute(RawVaribute raw, Dictionary<string, WineVar> vars, Dictionary<string, WineAttr> attrs, Dictionary<string, WineCult> cults) :
diff --git a/Elwig/Models/Entities/AT_Gem.cs b/Elwig/Models/Entities/AT_Gem.cs
index 6e8d0b0..8647bd5 100644
--- a/Elwig/Models/Entities/AT_Gem.cs
+++ b/Elwig/Models/Entities/AT_Gem.cs
@@ -9,10 +9,10 @@ namespace Elwig.Models.Entities {
         public int Gkz { get; private set; }
 
         [Column("name")]
-        public string Name { get; private set; }
+        public string Name { get; private set; } = null!;
 
         [InverseProperty("Gem")]
-        public virtual ISet<AT_Kg> Kgs { get; private set; }
+        public virtual ISet<AT_Kg> Kgs { get; private set; } = null!;
 
         [InverseProperty("AtGem")]
         public virtual WbGem? WbGem { get; private set; }
diff --git a/Elwig/Models/Entities/AT_Kg.cs b/Elwig/Models/Entities/AT_Kg.cs
index 0a2191e..22cdf11 100644
--- a/Elwig/Models/Entities/AT_Kg.cs
+++ b/Elwig/Models/Entities/AT_Kg.cs
@@ -11,10 +11,10 @@ namespace Elwig.Models.Entities {
         public int Gkz { get; private set; }
 
         [Column("name")]
-        public string Name { get; private set; }
+        public string Name { get; private set; } = null!;
 
         [ForeignKey("Gkz")]
-        public virtual AT_Gem Gem { get; private set; }
+        public virtual AT_Gem Gem { get; private set; } = null!;
 
         [InverseProperty("AtKg")]
         public virtual WbKg? WbKg { get; private set; }
diff --git a/Elwig/Models/Entities/AT_Ort.cs b/Elwig/Models/Entities/AT_Ort.cs
index fc7829b..a2cdaf4 100644
--- a/Elwig/Models/Entities/AT_Ort.cs
+++ b/Elwig/Models/Entities/AT_Ort.cs
@@ -14,10 +14,10 @@ namespace Elwig.Models.Entities {
         public int? KgNr { get; private set; }
 
         [Column("name")]
-        public string Name { get; private set; }
+        public string Name { get; private set; } = null!;
 
         [ForeignKey("Gkz")]
-        public virtual AT_Gem Gem { get; private set; }
+        public virtual AT_Gem Gem { get; private set; } = null!;
 
         [ForeignKey("KgNr")]
         public virtual AT_Kg? Kg { get; private set; }
diff --git a/Elwig/Models/Entities/AT_Plz.cs b/Elwig/Models/Entities/AT_Plz.cs
index 5d00e81..7267516 100644
--- a/Elwig/Models/Entities/AT_Plz.cs
+++ b/Elwig/Models/Entities/AT_Plz.cs
@@ -9,13 +9,13 @@ namespace Elwig.Models.Entities {
         public int Plz { get; private set; }
 
         [Column("ort")]
-        public string Ort { get; private set; }
+        public string Ort { get; private set; } = null!;
 
         [Column("blnr")]
         public int BlNr { get; private set; }
 
         [Column("type")]
-        public string Type { get; private set; }
+        public string Type { get; private set; } = null!;
 
         [Column("internal")]
         public bool IsInternal { get; private set; }
@@ -27,6 +27,6 @@ namespace Elwig.Models.Entities {
         public bool IsPoBox { get; private set; }
 
         [InverseProperty("AtPlz")]
-        public virtual ISet<AT_PlzDest> Orte { get; private set; }
+        public virtual ISet<AT_PlzDest> Orte { get; private set; } = null!;
     }
 }
diff --git a/Elwig/Models/Entities/AT_PlzDest.cs b/Elwig/Models/Entities/AT_PlzDest.cs
index 9c618d7..00bf8e6 100644
--- a/Elwig/Models/Entities/AT_PlzDest.cs
+++ b/Elwig/Models/Entities/AT_PlzDest.cs
@@ -15,18 +15,18 @@ namespace Elwig.Models.Entities {
         public int CountryNum { get; private set; }
 
         [Column("id")]
-        public string Id { get; private set;  }
+        public string Id { get; private set; } = null!;
 
         [Column("dest")]
-        public string Dest { get; private set; }
+        public string Dest { get; private set; } = null!;
 
         [ForeignKey("Plz")]
-        public virtual AT_Plz AtPlz { get; private set; }
+        public virtual AT_Plz AtPlz { get; private set; } = null!;
 
         [ForeignKey("Okz")]
-        public virtual AT_Ort Ort { get; private set; }
+        public virtual AT_Ort Ort { get; private set; } = null!;
 
         [ForeignKey("CountryNum")]
-        public virtual Country Country { get; private set; }
+        public virtual Country Country { get; private set; } = null!;
     }
 }
diff --git a/Elwig/Models/Entities/AreaCom.cs b/Elwig/Models/Entities/AreaCom.cs
index 4878f9d..07278b1 100644
--- a/Elwig/Models/Entities/AreaCom.cs
+++ b/Elwig/Models/Entities/AreaCom.cs
@@ -2,7 +2,6 @@ using Elwig.Helpers;
 using Microsoft.EntityFrameworkCore;
 using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations.Schema;
-using System.Linq;
 
 namespace Elwig.Models.Entities {
     [Table("area_commitment"), PrimaryKey("FbNr")]
@@ -14,7 +13,7 @@ namespace Elwig.Models.Entities {
         public int MgNr { get; set; }
 
         [Column("vtrgid")]
-        public string VtrgId { get; set; }
+        public required string VtrgId { get; set; }
 
         [Column("cultid")]
         public string? CultId { get; set; }
@@ -26,7 +25,7 @@ namespace Elwig.Models.Entities {
         public int KgNr { get; set; }
 
         [Column("gstnr")]
-        public string GstNr { get; set; }
+        public required string GstNr { get; set; }
 
         [Column("rdnr")]
         public int? RdNr { get; set; }
@@ -41,25 +40,24 @@ namespace Elwig.Models.Entities {
         public string? Comment { get; set; }
 
         [ForeignKey("MgNr")]
-        public virtual Member Member { get; private set; }
+        public virtual Member Member { get; private set; } = null!;
 
         [ForeignKey("VtrgId")]
-        public virtual AreaComType AreaComType { get; private set; }
+        public virtual AreaComType AreaComType { get; private set; } = null!;
 
         [ForeignKey("CultId")]
         public virtual WineCult? WineCult { get; private set; }
 
         [ForeignKey("KgNr")]
-        public virtual WbKg Kg { get; private set; }
+        public virtual WbKg Kg { get; private set; } = null!;
 
         [ForeignKey("KgNr, RdNr")]
         public virtual WbRd? Rd { get; private set; }
 
         public int SearchScore(IEnumerable<string> keywords) {
-            var list = new string?[] {
-                WineCult?.Name, Kg.AtKg.Name, Rd.Name, GstNr, Comment,
-            }.ToList();
-            return Utils.GetSearchScore(list, keywords);
+            return Utils.GetSearchScore([
+                 WineCult?.Name, Kg.AtKg.Name, Rd?.Name, GstNr, Comment,
+            ], keywords);
         }
     }
 }
diff --git a/Elwig/Models/Entities/AreaComType.cs b/Elwig/Models/Entities/AreaComType.cs
index cadd183..99857ea 100644
--- a/Elwig/Models/Entities/AreaComType.cs
+++ b/Elwig/Models/Entities/AreaComType.cs
@@ -7,10 +7,10 @@ namespace Elwig.Models.Entities {
     [Table("area_commitment_type"), PrimaryKey("VtrgId"), Index("SortId", "AttrId", "Discriminator", IsUnique = true)]
     public class AreaComType {
         [Column("vtrgid")]
-        public string VtrgId { get; set; }
+        public required string VtrgId { get; set; }
 
         [Column("sortid")]
-        public string SortId { get; set; }
+        public required string SortId { get; set; }
 
         [Column("attrid")]
         public string? AttrId { get; set; }
@@ -46,7 +46,7 @@ namespace Elwig.Models.Entities {
         }
 
         [ForeignKey("SortId")]
-        public virtual WineVar WineVar { get; private set; }
+        public virtual WineVar WineVar { get; private set; } = null!;
 
         [ForeignKey("AttrId")]
         public virtual WineAttr? WineAttr { get; private set; }
diff --git a/Elwig/Models/Entities/BillingAddr.cs b/Elwig/Models/Entities/BillingAddr.cs
index 2ceca41..fa0d9bc 100644
--- a/Elwig/Models/Entities/BillingAddr.cs
+++ b/Elwig/Models/Entities/BillingAddr.cs
@@ -9,24 +9,24 @@ namespace Elwig.Models.Entities {
         public int MgNr { get; set; }
 
         [Column("name")]
-        public string Name { get; set; }
+        public required string Name { get; set; }
 
         [Column("country")]
         public int CountryNum { get; set; }
 
         [Column("postal_dest")]
-        public string PostalDestId { get; set; }
+        public required string PostalDestId { get; set; }
 
         [Column("address")]
-        public string Address { get; set; }
+        public required string Address { get; set; }
 
         [ForeignKey("MgNr")]
-        public virtual Member Member { get; private set; }
+        public virtual Member Member { get; private set; } = null!;
 
         [ForeignKey("CountryNum")]
-        public virtual Country Country { get; private set; }
+        public virtual Country Country { get; private set; } = null!;
 
         [ForeignKey("CountryNum, PostalDestId")]
-        public virtual PostalDest PostalDest { get; private set; }
+        public virtual PostalDest PostalDest { get; private set; } = null!;
     }
 }
diff --git a/Elwig/Models/Entities/Branch.cs b/Elwig/Models/Entities/Branch.cs
index 81d5c7c..4c0027b 100644
--- a/Elwig/Models/Entities/Branch.cs
+++ b/Elwig/Models/Entities/Branch.cs
@@ -7,10 +7,10 @@ namespace Elwig.Models.Entities {
     [Table("branch"), PrimaryKey("ZwstId"), Index("Name", IsUnique = true)]
     public class Branch {
         [Column("zwstid")]
-        public string ZwstId { get; set; }
+        public required string ZwstId { get; set; }
 
         [Column("name")]
-        public string Name { get; set; }
+        public required string Name { get; set; }
 
         [Column("country")]
         public int? CountryNum { get; set; }
@@ -37,6 +37,6 @@ namespace Elwig.Models.Entities {
         public string? MobileNr { get; set; }
 
         [InverseProperty("Branch")]
-        public virtual ISet<Member> Members { get; private set; }
+        public virtual ISet<Member> Members { get; private set; } = null!;
     }
 }
diff --git a/Elwig/Models/Entities/ClientParam.cs b/Elwig/Models/Entities/ClientParam.cs
index c9414a6..1dee8d1 100644
--- a/Elwig/Models/Entities/ClientParam.cs
+++ b/Elwig/Models/Entities/ClientParam.cs
@@ -5,7 +5,7 @@ namespace Elwig.Models.Entities {
     [Table("client_parameter"), PrimaryKey("Param")]
     public class ClientParam {
         [Column("param")]
-        public string Param { get; set; }
+        public required string Param { get; set; }
 
         [Column("value")]
         public string? Value { get; set; }
diff --git a/Elwig/Models/Entities/Country.cs b/Elwig/Models/Entities/Country.cs
index 73756fb..e6ff026 100644
--- a/Elwig/Models/Entities/Country.cs
+++ b/Elwig/Models/Entities/Country.cs
@@ -9,13 +9,13 @@ namespace Elwig.Models.Entities {
         public int Num { get; private set; }
 
         [Column("alpha2")]
-        public string Alpha2 { get; private set; }
+        public string Alpha2 { get; private set; } = null!;
 
         [Column("alpha3")]
-        public string Alpha3 { get; private set; }
+        public string Alpha3 { get; private set; } = null!;
 
         [Column("name")]
-        public string Name { get; private set; }
+        public string Name { get; private set; } = null!;
 
         [Column("is_visible")]
         public bool IsVisible { get; private set; }
diff --git a/Elwig/Models/Entities/Credit.cs b/Elwig/Models/Entities/Credit.cs
index 91dd1eb..e75ed9a 100644
--- a/Elwig/Models/Entities/Credit.cs
+++ b/Elwig/Models/Entities/Credit.cs
@@ -94,12 +94,12 @@ namespace Elwig.Models.Entities {
         public DateTime ModifiedTimestamp => DateTimeOffset.FromUnixTimeSeconds(CTime).LocalDateTime;
 
         [ForeignKey("Year, AvNr, MgNr")]
-        public virtual PaymentMember Payment { get; private set; }
+        public virtual PaymentMember Payment { get; private set; } = null!;
 
         [ForeignKey("Year, AvNr")]
-        public virtual PaymentVar Variant { get; private set; }
+        public virtual PaymentVar Variant { get; private set; } = null!;
 
         [ForeignKey("MgNr")]
-        public virtual Member Member { get; private set; }
+        public virtual Member Member { get; private set; } = null!;
     }
 }
diff --git a/Elwig/Models/Entities/Currency.cs b/Elwig/Models/Entities/Currency.cs
index a7f809c..a35db6b 100644
--- a/Elwig/Models/Entities/Currency.cs
+++ b/Elwig/Models/Entities/Currency.cs
@@ -6,10 +6,10 @@ namespace Elwig.Models.Entities {
     [Table("currency"), PrimaryKey("Code")]
     public class Currency {
         [Column("code")]
-        public string Code { get; private set; }
+        public string Code { get; private set; } = null!;
 
         [Column("name")]
-        public string Name { get; private set; }
+        public string Name { get; private set; } = null!;
 
         [Column("symbol")]
         public string? Symbol { get; private set; }
diff --git a/Elwig/Models/Entities/Delivery.cs b/Elwig/Models/Entities/Delivery.cs
index c05f079..39e61d8 100644
--- a/Elwig/Models/Entities/Delivery.cs
+++ b/Elwig/Models/Entities/Delivery.cs
@@ -16,7 +16,7 @@ namespace Elwig.Models.Entities {
         public int DId { get; set; }
 
         [Column("date")]
-        public string DateString { get; set; }
+        public required string DateString { get; set; }
 
         [NotMapped]
         public DateOnly Date {
@@ -43,31 +43,31 @@ namespace Elwig.Models.Entities {
         }
 
         [Column("zwstid")]
-        public string ZwstId { get; set; }
+        public required string ZwstId { get; set; }
 
         [ForeignKey("ZwstId")]
-        public virtual Branch Branch { get; private set; }
+        public virtual Branch Branch { get; private set; } = null!;
 
         [Column("lnr")]
         public int LNr { get; set; }
 
         [Column("lsnr")]
-        public string LsNr { get; set; }
+        public required string LsNr { get; set; }
 
         [Column("mgnr")]
         public int MgNr { get; set; }
 
         [ForeignKey("MgNr")]
-        public virtual Member Member { get; private set; }
+        public virtual Member Member { get; private set; } = null!;
 
         [Column("comment")]
         public string? Comment { get; set; }
 
         [ForeignKey("Year")]
-        public virtual Season Season { get; private set; }
+        public virtual Season Season { get; private set; } = null!;
 
         [InverseProperty("Delivery")]
-        public virtual ISet<DeliveryPart> Parts { get; private set; }
+        public virtual ISet<DeliveryPart> Parts { get; private set; } = null!;
         [NotMapped]
         public IEnumerable<DeliveryPart> FilteredParts => PartFilter == null ? Parts : Parts.Where(p => PartFilter(p));
 
diff --git a/Elwig/Models/Entities/DeliveryPart.cs b/Elwig/Models/Entities/DeliveryPart.cs
index 4c15525..d16d9b0 100644
--- a/Elwig/Models/Entities/DeliveryPart.cs
+++ b/Elwig/Models/Entities/DeliveryPart.cs
@@ -14,16 +14,16 @@ namespace Elwig.Models.Entities {
         public int DId { get; set; }
 
         [ForeignKey("Year, DId")]
-        public virtual Delivery Delivery { get; private set; }
+        public virtual Delivery Delivery { get; private set; } = null!;
 
         [Column("dpnr")]
         public int DPNr { get; set; }
 
         [Column("sortid")]
-        public string SortId { get; set; }
+        public required string SortId { get; set; }
 
         [ForeignKey("SortId")]
-        public virtual WineVar Variety { get; private set; }
+        public virtual WineVar Variety { get; private set; } = null!;
 
         [Column("attrid")]
         public string? AttrId { get; set; }
@@ -49,16 +49,16 @@ namespace Elwig.Models.Entities {
         }
 
         [Column("qualid")]
-        public string QualId { get; set; }
+        public required string QualId { get; set; }
 
         [ForeignKey("QualId")]
-        public virtual WineQualLevel Quality { get; private set; }
+        public virtual WineQualLevel Quality { get; private set; } = null!;
 
         [Column("hkid")]
-        public string HkId { get; set; }
+        public required string HkId { get; set; }
 
         [ForeignKey("HkId")]
-        public virtual WineOrigin Origin { get; private set; }
+        public virtual WineOrigin Origin { get; private set; } = null!;
 
         [Column("kgnr")]
         public int? KgNr { get; set; }
@@ -109,7 +109,7 @@ namespace Elwig.Models.Entities {
         public string? Comment { get; set; }
 
         [InverseProperty("Part")]
-        public virtual ISet<DeliveryPartModifier> PartModifiers { get; private set; }
+        public virtual ISet<DeliveryPartModifier> PartModifiers { get; private set; } = null!;
 
         [NotMapped]
         public IEnumerable<Modifier> Modifiers => PartModifiers.Select(m => m.Modifier).OrderBy(m => m.Ordering);
@@ -121,6 +121,6 @@ namespace Elwig.Models.Entities {
         public string OriginString => Origin.OriginString + "\n" + (Kg?.Gl != null ? $" / {Kg.Gl.Name}" : "") + (Kg != null ? $" / {Kg.AtKg.Gem.Name} / KG {Kg.AtKg.Name}" : "") + (Rd != null ? $" / Ried {Rd.Name}" : "");
 
         [InverseProperty("Part")]
-        public virtual ISet<DeliveryPartBucket> Buckets { get; private set; }
+        public virtual ISet<DeliveryPartBucket> Buckets { get; private set; } = null!;
     }
 }
diff --git a/Elwig/Models/Entities/DeliveryPartBucket.cs b/Elwig/Models/Entities/DeliveryPartBucket.cs
index f53f704..dffce8f 100644
--- a/Elwig/Models/Entities/DeliveryPartBucket.cs
+++ b/Elwig/Models/Entities/DeliveryPartBucket.cs
@@ -17,12 +17,12 @@ namespace Elwig.Models.Entities {
         public int BktNr { get; set; }
 
         [Column("discr")]
-        public string Discr { get; set; }
+        public required string Discr { get; set; }
 
         [Column("value")]
         public int Value { get; set; }
 
         [ForeignKey("Year, DId, DPNr")]
-        public virtual DeliveryPart Part { get; private set; }
+        public virtual DeliveryPart Part { get; private set; } = null!;
     }
 }
diff --git a/Elwig/Models/Entities/DeliveryPartModifier.cs b/Elwig/Models/Entities/DeliveryPartModifier.cs
index 50e116f..c142c5a 100644
--- a/Elwig/Models/Entities/DeliveryPartModifier.cs
+++ b/Elwig/Models/Entities/DeliveryPartModifier.cs
@@ -14,12 +14,12 @@ namespace Elwig.Models.Entities {
         public int DPNr { get; set; }
 
         [ForeignKey("Year, DId, DPNr")]
-        public virtual DeliveryPart Part { get; private set; }
+        public virtual DeliveryPart Part { get; private set; } = null!;
 
         [Column("modid")]
-        public string ModId { get; set; }
+        public required string ModId { get; set; }
 
         [ForeignKey("Year, ModId")]
-        public virtual Modifier Modifier { get; private set; }
+        public virtual Modifier Modifier { get; private set; } = null!;
     }
 }
diff --git a/Elwig/Models/Entities/Member.cs b/Elwig/Models/Entities/Member.cs
index 01fe45a..32a9d6a 100644
--- a/Elwig/Models/Entities/Member.cs
+++ b/Elwig/Models/Entities/Member.cs
@@ -18,19 +18,19 @@ namespace Elwig.Models.Entities {
         public string? Prefix { get; set; }
 
         [Column("given_name")]
-        public string GivenName { get; set; }
+        public required string GivenName { get; set; }
 
         [Column("middle_names")]
         public string? MiddleName { get; set; }
 
         [NotMapped]
         public string[] MiddleNames {
-            get { return (MiddleName != null) ? MiddleName.Split(" ") : Array.Empty<string>(); }
-            set { MiddleName = (value.Length > 0) ? string.Join(" ", value) : null; }
+            get => (MiddleName != null) ? MiddleName.Split(" ") : [];
+            set => MiddleName = (value.Length > 0) ? string.Join(" ", value) : null;
         }
 
         [Column("family_name")]
-        public string FamilyName { get; set; }
+        public required string FamilyName { get; set; }
 
         [Column("suffix")]
         public string? Suffix { get; set; }
@@ -118,10 +118,10 @@ namespace Elwig.Models.Entities {
         public int CountryNum { get; set; }
 
         [Column("postal_dest")]
-        public string PostalDestId { get; set; }
+        public string PostalDestId { get; set; } = null!;
 
         [Column("address")]
-        public string Address { get; set; }
+        public string Address { get; set; } = null!;
 
         [Column("default_kgnr")]
         public int? DefaultKgNr { get; set; }
@@ -139,10 +139,10 @@ namespace Elwig.Models.Entities {
         public virtual Member? Predecessor { get; private set; }
 
         [ForeignKey("CountryNum")]
-        public virtual Country Country { get; private set; }
+        public virtual Country Country { get; private set; } = null!;
 
         [ForeignKey("CountryNum, PostalDestId")]
-        public virtual PostalDest PostalDest { get; private set; }
+        public virtual PostalDest PostalDest { get; private set; } = null!;
 
         [ForeignKey("DefaultKgNr")]
         public virtual WbKg? DefaultWbKg { get; private set; }
@@ -154,7 +154,7 @@ namespace Elwig.Models.Entities {
         public virtual Branch? Branch { get; private set; }
 
         [InverseProperty("Member")]
-        public virtual ISet<AreaCom> AreaCommitments { get; private set; }
+        public virtual ISet<AreaCom> AreaCommitments { get; private set; } = null!;
 
         [NotMapped]
         public IEnumerable<AreaCom> ActiveAreaCommitments => AreaCommitments
@@ -164,22 +164,22 @@ namespace Elwig.Models.Entities {
         public virtual BillingAddr? BillingAddress { get; private set; }
 
         [InverseProperty("Member")]
-        public virtual ISet<Delivery> Deliveries { get; private set; }
+        public virtual ISet<Delivery> Deliveries { get; private set; } = null!;
 
         [InverseProperty("Member")]
-        public virtual ISet<MemberTelNr> TelephoneNumbers { get; private set; }
+        public virtual ISet<MemberTelNr> TelephoneNumbers { get; private set; } = null!;
 
         [InverseProperty("member")]
-        public virtual ISet<MemberEmailAddr> EmailAddresses { get; private set; }
+        public virtual ISet<MemberEmailAddr> EmailAddresses { get; private set; } = null!;
 
-        public string FullAddress => $"{Address}, {PostalDest.AtPlz.Plz} {PostalDest.AtPlz.Ort.Name}";
+        public string FullAddress => $"{Address}, {PostalDest.AtPlz?.Plz} {PostalDest.AtPlz?.Ort.Name}";
 
         public int SearchScore(IEnumerable<string> keywords) {
-            return Utils.GetSearchScore(new string?[] {
+            return Utils.GetSearchScore([
                 FamilyName, MiddleName, GivenName,
                 BillingAddress?.Name,
                 Comment,
-            }, keywords);
+            ], keywords);
         }
     }
 }
diff --git a/Elwig/Models/Entities/MemberEmailAddr.cs b/Elwig/Models/Entities/MemberEmailAddr.cs
index 7b96db9..f9aa83b 100644
--- a/Elwig/Models/Entities/MemberEmailAddr.cs
+++ b/Elwig/Models/Entities/MemberEmailAddr.cs
@@ -11,12 +11,12 @@ namespace Elwig.Models.Entities {
         public int Nr { get; set; }
 
         [Column("address")]
-        public string Address { get; set; }
+        public required string Address { get; set; }
 
         [Column("comment")]
         public string? Comment { get; set; }
 
         [ForeignKey("MgNr")]
-        public virtual Member Member { get; private set; }
+        public virtual Member Member { get; private set; } = null!;
     }
 }
diff --git a/Elwig/Models/Entities/MemberHistory.cs b/Elwig/Models/Entities/MemberHistory.cs
index 3835581..e968407 100644
--- a/Elwig/Models/Entities/MemberHistory.cs
+++ b/Elwig/Models/Entities/MemberHistory.cs
@@ -9,7 +9,7 @@ namespace Elwig.Models.Entities {
         public int MgNr { get; set; }
 
         [Column("date")]
-        public string DateString { get; set; }
+        public required string DateString { get; set; }
         [NotMapped]
         public DateOnly Date {
             get => DateOnly.ParseExact(DateString, "yyyy-MM-dd");
@@ -20,12 +20,12 @@ namespace Elwig.Models.Entities {
         public int BusinessShares { get; set; }
 
         [Column("type")]
-        public string Type { get; set; }
+        public required string Type { get; set; }
 
         [Column("comment")]
         public string? Comment { get; set; }
 
         [ForeignKey("MgNr")]
-        public virtual Member Member { get; private set; }
+        public virtual Member Member { get; private set; } = null!;
     }
 }
diff --git a/Elwig/Models/Entities/MemberTelNr.cs b/Elwig/Models/Entities/MemberTelNr.cs
index dbcddb7..2078de7 100644
--- a/Elwig/Models/Entities/MemberTelNr.cs
+++ b/Elwig/Models/Entities/MemberTelNr.cs
@@ -11,15 +11,15 @@ namespace Elwig.Models.Entities {
         public int Nr { get; set; }
 
         [Column("type")]
-        public string Type { get; set; }
+        public required string Type { get; set; }
 
         [Column("number")]
-        public string Number { get; set; }
+        public required string Number { get; set; }
 
         [Column("comment")]
         public string? Comment { get; set; }
 
         [ForeignKey("MgNr")]
-        public virtual Member Member { get; private set; }
+        public virtual Member Member { get; private set; } = null!;
     }
 }
diff --git a/Elwig/Models/Entities/Modifier.cs b/Elwig/Models/Entities/Modifier.cs
index 9261124..d4e67c4 100644
--- a/Elwig/Models/Entities/Modifier.cs
+++ b/Elwig/Models/Entities/Modifier.cs
@@ -11,13 +11,13 @@ namespace Elwig.Models.Entities {
         public int Year { get; set; }
 
         [Column("modid")]
-        public string ModId { get; set; }
+        public required string ModId { get; set; }
 
         [Column("ordering")]
         public int Ordering { get; set; }
 
         [Column("name")]
-        public string Name { get; set; }
+        public required string Name { get; set; }
 
         [Column("abs")]
         public long? AbsValue { get; set; }
@@ -44,7 +44,7 @@ namespace Elwig.Models.Entities {
         public bool IsQuickSelect { get; set; }
 
         [ForeignKey("Year")]
-        public virtual Season Season { get; private set; }
+        public virtual Season Season { get; private set; } = null!;
 
         public string ValueStr =>
             (Abs != null) ? $"{Utils.GetSign(Abs.Value)}{Math.Abs(Abs.Value).ToString("0." + string.Concat(Enumerable.Repeat('0', Season.Precision)))}\u00a0{Season.Currency.Symbol}/kg" :
diff --git a/Elwig/Models/Entities/PaymentDeliveryPart.cs b/Elwig/Models/Entities/PaymentDeliveryPart.cs
index ab9eb42..498ddf9 100644
--- a/Elwig/Models/Entities/PaymentDeliveryPart.cs
+++ b/Elwig/Models/Entities/PaymentDeliveryPart.cs
@@ -46,9 +46,9 @@ namespace Elwig.Models.Entities {
         public decimal Amount => Variant.Season.DecFromDb(AmountValue);
 
         [ForeignKey("Year, AvNr")]
-        public virtual PaymentVar Variant { get; private set; }
+        public virtual PaymentVar Variant { get; private set; } = null!;
 
         [ForeignKey("Year, DId, DPNr")]
-        public virtual DeliveryPart DeliveryPart { get; private set; }
+        public virtual DeliveryPart DeliveryPart { get; private set; } = null!;
     }
 }
diff --git a/Elwig/Models/Entities/PaymentDeliveryPartBucket.cs b/Elwig/Models/Entities/PaymentDeliveryPartBucket.cs
index 03cb15e..3bb1655 100644
--- a/Elwig/Models/Entities/PaymentDeliveryPartBucket.cs
+++ b/Elwig/Models/Entities/PaymentDeliveryPartBucket.cs
@@ -36,9 +36,9 @@ namespace Elwig.Models.Entities {
         }
 
         [ForeignKey("Year, AvNr")]
-        public virtual PaymentVar Variant { get; private set; }
+        public virtual PaymentVar Variant { get; private set; } = null!;
 
         [ForeignKey("Year, DId, DPNr")]
-        public virtual DeliveryPart DeliveryPart { get; private set; }
+        public virtual DeliveryPart DeliveryPart { get; private set; } = null!;
     }
 }
diff --git a/Elwig/Models/Entities/PaymentMember.cs b/Elwig/Models/Entities/PaymentMember.cs
index d16d6c4..7af44e2 100644
--- a/Elwig/Models/Entities/PaymentMember.cs
+++ b/Elwig/Models/Entities/PaymentMember.cs
@@ -13,7 +13,6 @@ namespace Elwig.Models.Entities {
         [Column("mgnr")]
         public int MgNr { get; set; }
 
-
         [Column("net_amount")]
         public long NetAmountValue { get; set; }
         [NotMapped]
@@ -44,10 +43,10 @@ namespace Elwig.Models.Entities {
         public decimal Amount => Variant.Season.DecFromDb(AmountValue);
 
         [ForeignKey("Year, AvNr")]
-        public virtual PaymentVar Variant { get; private set; }
+        public virtual PaymentVar Variant { get; private set; } = null!;
 
         [ForeignKey("MgNr")]
-        public virtual Member Member { get; private set; }
+        public virtual Member Member { get; private set; } = null!;
 
         [InverseProperty("Payment")]
         public virtual Credit? Credit { get; private set; }
diff --git a/Elwig/Models/Entities/PaymentVar.cs b/Elwig/Models/Entities/PaymentVar.cs
index 505236c..0cf553b 100644
--- a/Elwig/Models/Entities/PaymentVar.cs
+++ b/Elwig/Models/Entities/PaymentVar.cs
@@ -13,10 +13,10 @@ namespace Elwig.Models.Entities {
         public int AvNr { get; set; }
 
         [Column("name")]
-        public string Name { get; set; }
+        public required string Name { get; set; }
 
         [Column("date")]
-        public string DateString { get; set; }
+        public required string DateString { get; set; }
 
         [NotMapped]
         public DateOnly Date {
@@ -43,18 +43,18 @@ namespace Elwig.Models.Entities {
         public string? Comment { get; set; }
 
         [Column("data")]
-        public string Data { get; set; }
+        public required string Data { get; set; }
 
         [ForeignKey("Year")]
-        public virtual Season Season { get; private set; }
+        public virtual Season Season { get; private set; } = null!;
 
         [InverseProperty("Variant")]
-        public virtual ISet<PaymentMember> MemberPayments { get; private set; }
+        public virtual ISet<PaymentMember> MemberPayments { get; private set; } = null!;
 
         [InverseProperty("Variant")]
-        public virtual ISet<PaymentDeliveryPart> DeliveryPartPayments { get; private set; }
+        public virtual ISet<PaymentDeliveryPart> DeliveryPartPayments { get; private set; } = null!;
 
         [InverseProperty("Variant")]
-        public virtual ISet<Credit> Credits { get; private set; }
+        public virtual ISet<Credit> Credits { get; private set; } = null!;
     }
 }
diff --git a/Elwig/Models/Entities/PostalDest.cs b/Elwig/Models/Entities/PostalDest.cs
index d350a12..1347ab8 100644
--- a/Elwig/Models/Entities/PostalDest.cs
+++ b/Elwig/Models/Entities/PostalDest.cs
@@ -8,10 +8,10 @@ namespace Elwig.Models.Entities {
         public int CountryNum { get; private set; }
 
         [Column("id")]
-        public string Id { get; private set; }
+        public string Id { get; private set; } = null!;
 
         [ForeignKey("CountryNum")]
-        public virtual Country Country { get; private set; }
+        public virtual Country Country { get; private set; } = null!;
 
         [ForeignKey("Id")]
         public virtual AT_PlzDest? AtPlz { get; private set; }
diff --git a/Elwig/Models/Entities/Season.cs b/Elwig/Models/Entities/Season.cs
index d96e6fe..6ee1f2e 100644
--- a/Elwig/Models/Entities/Season.cs
+++ b/Elwig/Models/Entities/Season.cs
@@ -11,7 +11,7 @@ namespace Elwig.Models.Entities {
         public int Year { get; set; }
 
         [Column("currency")]
-        public string CurrencyCode { get; set; }
+        public required string CurrencyCode { get; set; }
 
         [Column("precision")]
         public byte Precision { get; set; }
@@ -98,16 +98,16 @@ namespace Elwig.Models.Entities {
         }
 
         [ForeignKey("CurrencyCode")]
-        public virtual Currency Currency { get; private set; }
+        public virtual Currency Currency { get; private set; } = null!;
 
         [InverseProperty("Season")]
-        public virtual ISet<Modifier> Modifiers { get; private set; }
+        public virtual ISet<Modifier> Modifiers { get; private set; } = null!;
 
         [InverseProperty("Season")]
-        public virtual ISet<PaymentVar> PaymentVariants { get; private set; }
+        public virtual ISet<PaymentVar> PaymentVariants { get; private set; } = null!;
 
         [InverseProperty("Season")]
-        public virtual ISet<Delivery> Deliveries { get; private set; }
+        public virtual ISet<Delivery> Deliveries { get; private set; } = null!;
 
         public decimal DecFromDb(long value) {
             return Utils.DecFromDb(value, Precision);
diff --git a/Elwig/Models/Entities/WbGem.cs b/Elwig/Models/Entities/WbGem.cs
index 7e49707..554be05 100644
--- a/Elwig/Models/Entities/WbGem.cs
+++ b/Elwig/Models/Entities/WbGem.cs
@@ -8,12 +8,12 @@ namespace Elwig.Models.Entities {
         public int Gkz { get; private set; }
 
         [Column("hkid")]
-        public string HkId { get; private set; }
+        public string HkId { get; private set; } = null!;
 
         [ForeignKey("Gkz")]
-        public virtual AT_Gem AtGem { get; private set; }
+        public virtual AT_Gem AtGem { get; private set; } = null!;
 
         [ForeignKey("HkId")]
-        public virtual WineOrigin Origin { get; private set; }
+        public virtual WineOrigin Origin { get; private set; } = null!;
     }
 }
diff --git a/Elwig/Models/Entities/WbGl.cs b/Elwig/Models/Entities/WbGl.cs
index 56446ee..7542e00 100644
--- a/Elwig/Models/Entities/WbGl.cs
+++ b/Elwig/Models/Entities/WbGl.cs
@@ -9,9 +9,9 @@ namespace Elwig.Models.Entities {
         public int GlNr { get; private set; }
 
         [Column("name")]
-        public string Name { get; private set; }
+        public string Name { get; private set; } = null!;
 
         [InverseProperty("Gl")]
-        public virtual ISet<WbKg> Kgs { get; private set; }
+        public virtual ISet<WbKg> Kgs { get; private set; } = null!;
     }
 }
diff --git a/Elwig/Models/Entities/WbKg.cs b/Elwig/Models/Entities/WbKg.cs
index d960b1c..90b7ea0 100644
--- a/Elwig/Models/Entities/WbKg.cs
+++ b/Elwig/Models/Entities/WbKg.cs
@@ -12,19 +12,19 @@ namespace Elwig.Models.Entities {
         public int? GlNr { get; set; }
 
         [ForeignKey("KgNr")]
-        public virtual AT_Kg AtKg { get; private set; }
+        public virtual AT_Kg AtKg { get; private set; } = null!;
 
         [ForeignKey("GlNr")]
-        public virtual WbGl Gl { get; private set; }
+        public virtual WbGl Gl { get; private set; } = null!;
 
         [InverseProperty("Kg")]
-        public virtual ISet<WbRd> Rds { get; private set; }
+        public virtual ISet<WbRd> Rds { get; private set; } = null!;
 
         [InverseProperty("DefaultWbKg")]
-        public virtual ISet<Member> Members { get; private set; }
+        public virtual ISet<Member> Members { get; private set; } = null!;
 
         [NotMapped]
-        public WbGem Gem => AtKg.Gem.WbGem;
+        public WbGem Gem => AtKg.Gem.WbGem!;
 
         [NotMapped]
         public WineOrigin Origin => Gem.Origin;
diff --git a/Elwig/Models/Entities/WbRd.cs b/Elwig/Models/Entities/WbRd.cs
index fec0df5..769e56c 100644
--- a/Elwig/Models/Entities/WbRd.cs
+++ b/Elwig/Models/Entities/WbRd.cs
@@ -11,9 +11,9 @@ namespace Elwig.Models.Entities {
         public int RdNr { get; set; }
         
         [Column("name")]
-        public string Name { get; set; }
+        public required string Name { get; set; }
 
         [ForeignKey("KgNr")]
-        public virtual WbKg Kg { get; private set; }
+        public virtual WbKg Kg { get; private set; } = null!;
     }
 }
diff --git a/Elwig/Models/Entities/WineAttr.cs b/Elwig/Models/Entities/WineAttr.cs
index 3f1328f..0202aab 100644
--- a/Elwig/Models/Entities/WineAttr.cs
+++ b/Elwig/Models/Entities/WineAttr.cs
@@ -6,10 +6,10 @@ namespace Elwig.Models.Entities {
     [Table("wine_attribute"), PrimaryKey("AttrId"), Index("Name", IsUnique = true)]
     public class WineAttr {
         [Column("attrid")]
-        public string AttrId { get; set; }
+        public required string AttrId { get; set; }
 
         [Column("name")]
-        public string Name { get; set; }
+        public required string Name { get; set; }
 
         [Column("active")]
         public bool IsActive { get; set; }
@@ -23,13 +23,6 @@ namespace Elwig.Models.Entities {
         [Column("fill_lower")]
         public int FillLower { get; set; }
 
-        public WineAttr() { }
-
-        public WineAttr(string attrId, string name) {
-            AttrId = attrId;
-            Name = name;
-        }
-
         public override string ToString() {
             return Name;
         }
diff --git a/Elwig/Models/Entities/WineCult.cs b/Elwig/Models/Entities/WineCult.cs
index fed7738..62f5f4e 100644
--- a/Elwig/Models/Entities/WineCult.cs
+++ b/Elwig/Models/Entities/WineCult.cs
@@ -6,21 +6,14 @@ namespace Elwig.Models.Entities {
     [Table("wine_cultivation"), PrimaryKey("CultId"), Index("Name", IsUnique = true)]
     public class WineCult {
         [Column("cultid")]
-        public string CultId { get; set; }
+        public required string CultId { get; set; }
 
         [Column("name")]
-        public string Name { get; set; }
+        public required string Name { get; set; }
 
         [Column("description")]
         public string? Description { get; set; }
 
-        public WineCult() { }
-
-        public WineCult(string cultId, string name) {
-            CultId = cultId;
-            Name = name;
-        }
-
         public override string ToString() {
             return Name;
         }
diff --git a/Elwig/Models/Entities/WineOrigin.cs b/Elwig/Models/Entities/WineOrigin.cs
index a82fea9..9fbbf07 100644
--- a/Elwig/Models/Entities/WineOrigin.cs
+++ b/Elwig/Models/Entities/WineOrigin.cs
@@ -9,7 +9,7 @@ namespace Elwig.Models.Entities {
     [Table("wine_origin"), PrimaryKey("HkId"), Index("Name", IsUnique = true)]
     public class WineOrigin {
         [Column("hkid")]
-        public string HkId { get; private set; }
+        public string HkId { get; private set; } = null!;
 
         [Column("parent_hkid")]
         public string? ParentHkId { get; private set; }
@@ -18,16 +18,16 @@ namespace Elwig.Models.Entities {
         public virtual WineOrigin? Parent { get; private set; }
 
         [Column("name")]
-        public string Name { get; private set; }
+        public string Name { get; private set; } = null!;
 
         [Column("blnr")]
         public int? BlNr { get; private set; }
 
         [InverseProperty("Origin")]
-        public virtual ISet<WbGem> Gems { get; private set; }
+        public virtual ISet<WbGem> Gems { get; private set; } = null!;
 
         [InverseProperty("Parent")]
-        public virtual ISet<WineOrigin> Children { get; private set; }
+        public virtual ISet<WineOrigin> Children { get; private set; } = null!;
 
         public int Level => (Parent?.Level + 1) ?? 0;
 
diff --git a/Elwig/Models/Entities/WineQualLevel.cs b/Elwig/Models/Entities/WineQualLevel.cs
index a0bda18..b02600d 100644
--- a/Elwig/Models/Entities/WineQualLevel.cs
+++ b/Elwig/Models/Entities/WineQualLevel.cs
@@ -7,7 +7,7 @@ namespace Elwig.Models.Entities {
     [Table("wine_quality_level"), PrimaryKey("QualId")]
     public class WineQualLevel : IEquatable<WineQualLevel> {
         [Column("qualid")]
-        public string QualId { get; private set; }
+        public string QualId { get; private set; } = null!;
 
         [Column("origin_level")]
         public int? OriginLevel { get; private set; }
@@ -22,7 +22,7 @@ namespace Elwig.Models.Entities {
         public double? MinOe => MinKmw != null ? Utils.KmwToOe((double)MinKmw) : null;
 
         [Column("name")]
-        public string Name { get; private set; }
+        public string Name { get; private set; } = null!;
 
         public string MinKmwStr => (MinKmw == null) ? "" : $"(mind. {MinKmw:#.0}°)";
 
diff --git a/Elwig/Models/Entities/WineVar.cs b/Elwig/Models/Entities/WineVar.cs
index 3fec595..cbaec5f 100644
--- a/Elwig/Models/Entities/WineVar.cs
+++ b/Elwig/Models/Entities/WineVar.cs
@@ -5,13 +5,13 @@ namespace Elwig.Models.Entities {
     [Table("wine_variety"), PrimaryKey("SortId")]
     public class WineVar {
         [Column("sortid")]
-        public string SortId { get; private set; }
+        public string SortId { get; private set; } = null!;
 
         [Column("type")]
-        public string Type { get; private set; }
+        public string Type { get; private set; } = null!;
 
         [Column("name")]
-        public string Name { get; private set; }
+        public string Name { get; private set; } = null!;
 
         [Column("comment")]
         public string? Comment { get; private set; }
diff --git a/Elwig/Windows/BaseDataWindow.xaml.Mod.cs b/Elwig/Windows/BaseDataWindow.xaml.Mod.cs
index 5c1e520..965c7a7 100644
--- a/Elwig/Windows/BaseDataWindow.xaml.Mod.cs
+++ b/Elwig/Windows/BaseDataWindow.xaml.Mod.cs
@@ -103,7 +103,9 @@ namespace Elwig.Windows {
             _modChanged = true;
             var idx = (SeasonModifierList.SelectedIndex != -1) ? SeasonModifierList.SelectedIndex + 1 : _modList.Count;
             var item = new Modifier {
-                Year = s.Year
+                Year = s.Year,
+                ModId = "",
+                Name = "",
             };
             _modList.Insert(idx, item);
             SeasonModifierList.SelectedIndex = idx;
diff --git a/Tests/HelperTests/EbicsTest.cs b/Tests/HelperTests/EbicsTest.cs
index d84280b..4a3d90f 100644
--- a/Tests/HelperTests/EbicsTest.cs
+++ b/Tests/HelperTests/EbicsTest.cs
@@ -29,6 +29,8 @@ namespace Tests.HelperTests {
                 AvNr = 1,
                 Name = "Endauszahlung",
                 TransferDate = new DateOnly(2021, 6, 15),
+                Data = "",
+                DateString = "2021-01-31",
             };
             using var ctx = new AppDbContext();
             var members = ctx.Members.ToList();