Could not find conceptual model for type 'ModelType'

I'm currently trying to deploy a Silverlight app with a RIA services link to a Web Application Project. This app also uses Devart dotConnect for Oracle (an EF system for oracle).

When running MSBuild on the csproj file I am getting the error:

C:\Program Files (x86)\MSBuild\Microsoft\Silverlight\v3.0\Microsoft.Ria.Client.targets(261,5): error : Could not find the conceptual mod开发者_JS百科el type for 'ModelType'

Where ModelType is the name of one of the classes in the diagram.

Has anyone else ever come across this error? I am struggling to locate the root cause.

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This is a problem of Silverlight 3.
One of our users have already found a workaround for this:
* Change the file extension from .edml to .edmx
* Remove the Silverlight project from solution
* Compile solution using 64-bit MSBuild
Actually, upgrade to Silverlight 4 also solves the problem.