Visual Studio 2022 - Getting 'Object reference not set to an instance of an object' when using Entity Framework Core with In-Memory Database
I'm working on a personal project and I'm working with a frustrating scenario while trying to run unit tests in my .NET 6 application using Visual Studio 2022. I've set up an in-memory database with Entity Framework Core and when I attempt to add a new entity, I receive an behavior: `Object reference not set to an instance of an object`. Here's a snippet of the code where the scenario arises: ```csharp public class MyDbContext : DbContext { public DbSet<MyEntity> MyEntities { get; set; } public MyDbContext(DbContextOptions<MyDbContext> options) : base(options) {} } [TestClass] public class MyEntityTests { private MyDbContext _context; [TestInitialize] public void Setup() { var options = new DbContextOptionsBuilder<MyDbContext>() .UseInMemoryDatabase(databaseName: "TestDatabase") .Options; _context = new MyDbContext(options); } [TestMethod] public void AddNewEntity_ShouldWorkCorrectly() { var newEntity = new MyEntity { Name = "Test" }; _context.MyEntities.Add(newEntity); _context.SaveChanges(); // This line throws the exception } } ``` I've verified that my `MyEntity` class is defined correctly and has a public parameterless constructor. I also ensured that the in-memory database is being created without any issues. Before this, I added other entities without problems, so I'm not sure why this specific case is failing. Additionally, I tried debugging and saw that `newEntity` is not null, but when the `SaveChanges()` method is called, it throws the exception. I also tried setting up the database with different names to ensure no conflicts, but the same behavior continues. Any insights on why this might be happening or how to debug it further would be greatly appreciated. This is part of a larger API I'm building. I'd really appreciate any guidance on this. Thanks for any help you can provide!