I had the same problem upon launching Visual Studio 2013 Ultimate, and the solutions here didn't work for me. I tried deleting the mentioned folders and starting Visual Studio again, but it didn't work.
However I had other problems too, like Microsoft.visual studio package did not load correctly and also Page '312e8a59-2712-48a1-863e-0ef4e67961fc' not found VS 2012. The latter refers to a message in the Team Explorer window saying "Page 'somenumber' cannot be found".
So I run devenv /setup
on the Visual Studio command prompt with administrative rights. It did the job, and everything is fine now.