Visual Studio 2013 or 2015 EditorPackage did not load correctly constantly

This has become a popular question so I thought I add an explicit answer how to (at least) temporarily fix the problem as already stated in the question:

I stop Visual Studio and delete the following folder (completely, not just contents)

%LocalAppData%\Microsoft\VisualStudio\12.0\ComponentModelCache

If you are using VS2015, then the path should be:

%LocalAppData%\Microsoft\VisualStudio\14.0\ComponentModelCache

I don't keep a backup of the folder. It is created automatically again when starting Visual Studio.

I have never found a solution how to permanently fix the problem in that working environment. In my new developing environment (new projects and new workplace) the problem never happens.

from : https://stackoverflow.com/questions/29694329/visual-studio-2013-or-2015-editorpackage-did-not-load-correctly-constantly