Cryptic Linq to Entities message

I get the following message:

{"Entities in 'Entities.ApprovalRequests' participate in the 'FK_ApprovalRequest_Audit' relationship. 0 related 'Audit' were found. 1 'Audit' is expected."}

I'm stumped, does anyone know what to make of it?

My EDMX had the FK and is correct, yet every time I get this message.

How one would go to debug this, would be most usefu开发者_运维问答l.

You probably tried to persist an entity of type ApprovalRequests with no associated entity of type Audit while your entity model specifies that each ApprovalRequests must have (at least) one Audit.