Error Type:“The Web application at http://sharepointserver could not be found. Verify that you have ...

Question

 building applications in Visual Studio 2010 as Console applications or Windows Forms application,i got above error.

1. Under Project Properties –> Application, Ensure that the target framework to be compiled against is .NET Framework 3.5

 2. Under Project Properties –> Build, Ensure that the platform target is set to x64

Solved this error