Object reference not set to an instance of an object Exception On EntityFrameworkCore

 System.NullReferenceException

  Message=Object reference not set to an instance of an object.

  Source=Microsoft.EntityFrameworkCore.Relational

  StackTrace:

   at Microsoft.EntityFrameworkCore.Query.Internal.SplitQueryingEnumerable`1.Enumerator.Dispose()

   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)

   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)

This maybe a small problem caused by a value that is not nullable but the database has a null value, so c# cannot copy null to your variable and throws exception