Entity Framework Core: Data type 'nvarchar' is not supported in this form. Either specify the length explicitly in the type name, for example as 'nvarchar(16)', or remove the data type and use APIs such as HasMaxLength to allow EF choose the data type.

MyDbContext.cs

public class MyDbContext : MyContext
{
    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);

        modelBuilder.Entity<MyEntity>(entity =>
        {
            entity.Property(e => e.MyProperty)
                .HasColumnType("nvarchar(4000)");
        });
    }
}