Здравейте, колеги.

Ако някого е запознат с грешката, моля да сподели решение.

Грешката се появява при Import нa JSON обект и по - точно при добавянето в базата данни.

System.InvalidOperationException
  HResult=0x80131509
  Message=The instance of entity type 'ClientTruck' cannot be tracked because another instance with the key value '{ClientId: -2147482647, TruckId: 17}' is already being tracked. When attaching existing entities, ensure that only one entity instance with a given key value is attached.
  Source=Microsoft.EntityFrameworkCore
  StackTrace:
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.IdentityMap`1.ThrowIdentityConflict(InternalEntityEntry entry)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.IdentityMap`1.Add(TKey key, InternalEntityEntry entry, Boolean updateDuplicate)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.IdentityMap`1.Add(TKey key, InternalEntityEntry entry)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.NullableKeyIdentityMap`1.Add(InternalEntityEntry entry)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.StartTracking(InternalEntityEntry entry)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.InternalEntityEntry.SetEntityState(EntityState oldState, EntityState newState, Boolean acceptChanges, Boolean modifyProperties)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.InternalEntityEntry.SetEntityState(EntityState entityState, Boolean acceptChanges, Boolean modifyProperties, Nullable`1 forceStateWhenUnknownKey)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.EntityGraphAttacher.PaintAction(EntityEntryGraphNode`1 node)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.EntityEntryGraphIterator.TraverseGraph[TState](EntityEntryGraphNode`1 node, Func`2 handleNode)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.EntityEntryGraphIterator.TraverseGraph[TState](EntityEntryGraphNode`1 node, Func`2 handleNode)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.EntityGraphAttacher.AttachGraph(InternalEntityEntry rootEntry, EntityState targetState, EntityState storeGeneratedWithKeySetTargetState, Boolean forceStateWhenUnknownKey)
   at Microsoft.EntityFrameworkCore.DbContext.SetEntityState(InternalEntityEntry entry, EntityState entityState)
   at Microsoft.EntityFrameworkCore.DbContext.SetEntityStates(IEnumerable`1 entities, EntityState entityState)
   at Microsoft.EntityFrameworkCore.DbContext.AddRange(IEnumerable`1 entities)
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.AddRange(IEnumerable`1 entities)
   at Trucks.DataProcessor.Deserializer.ImportClient(TrucksContext context, String jsonString) in D:\programming\C# DB\DBAdvancedRetakeExam15August2022\Trucks\DataProcessor\Deserializer.cs:line 151
   at Trucks.StartUp.ImportEntities(TrucksContext context, String baseDir, String exportDir) in D:\programming\C# DB\DBAdvancedRetakeExam15August2022\Trucks\StartUp.cs:line 42
   at Trucks.StartUp.Main() in D:\programming\C# DB\DBAdvancedRetakeExam15August2022\Trucks\StartUp.cs:line 24