ayi <t>This means that the application is unable to load the EDMX. There are several things which can cause this.<br/> <br/> You might have changed the MetadataArtifactProcessing property of the model to Copy to Output Directory.<br/> <br/> The connection string could be wrong. I know you say you haven't changed it, but if you have changed other things (say, the name of an assembly), it could still be wrong.<br/> <br/> You might be using a post-compile task to embed the EDMX in the assembly, which is no longer working for some reason.<br/> <br/> In short, there is not really enough detail in your question to give an accurate answer, but hopefully these ideas should get you on the right track.<br/> <br/> Update: I've written a blog post with more complete steps for troubleshooting.</t>
