Entity Framework: Identity Errors

If you create a table with a PK that is not identity and then create a EF class from that and then try and load in an empty value, you get a System.Data.Update exception:

 

If you go ahead and change the server to identity without updating EF on your client, you still get a System.Data.Update exception, but with a different inner exception:

What you need to do is to fix it by changing to identity and then updating the EF on the client:

Volia: the change will now persist

However, if you create a PK on an existing table where there used to be a Implied key, you get an error. You need to drop the table and re-create.