We’ve been recently working on a Win Forms projects for the first time in a long time. Whilst working through the security and trying to implement Client Application Services following this we ran into a problem. By right clicking on the User Interface Project, then selecting “Properties”, then clicking the “Services Tab”, we got the following error, “Unspecified error (Exception from HRESULT: 0×80004005 (E_FAIL))”. We are using Visual Studio 2010 Ultimate, with .Net 4.0 Targeting.
We deleted the existing UI project and recreated it , added back our source code and presto it all worked again. My guess is the project file had become corrupted in some form.
We’re now up and running again, implementing our security providers and locking down our application.