If you are trying to use POCO classes in EF 4.0, it is relatively easy to run into problems with the mapping from your model to your CLR classes. If you get any nasty problems here, the best way to get to the bottom of things is to try to explicitly load the metadata for your POCO types. For example...

I’ve been playing around with creating a custom Astoria Data Service Provider , aka DSP, for a while now. So far I’d managed to get my metadata all setup, so browsing to $metadata works great. I’d got a few simple queries work. Basically everything was going fine. At least until I tried this URL: I wasn...