First off, I run the dev fabric on my virtual machine without problem. Just make sure that Visual Studio is launched as Admin. From the error you report it seems to be an issue with the registration of the association of your webrole with the Azure Project.
Try this: Right-click on the webrole node under the roles node in solution explorer under the Azure project node and reassociate your webrole with an "Existing project within the solution". Navigate to the csproj (or <lang>proj) of the web app and select it. Then do a clean rebuild of solution.
Hope this helps.
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