Little trick....that will help you long way

During the process of creating cloud project using VStudio, don't forget to mark external "reference" assemblies as "Copy Local =True". If this is not done, your application will run fine on your local cloud emulator but throw an "asp.net application error" when executed on the cloud. Every dll that is referenced, other than the default dlls, that are part of cloud project, should have property "copy local = true". When Visual Studio creates deployment package for cloud, it looks for this property. It adds all the dlls with "copy local = true" in the package and when the solution is deployed on the cloud, these additional dlls are deployed on the cloud too. In the absence of these dlls, your cloud application will throw “asp.net application error”.