This Visual Studio 2012 error can be easily rectified
" 'Microsoft.VisualStudio.Editor.Implementation.EditorPackage'
package did not load correctly".
Just delete the files and folders in
%LOCALAPPDATA%\Microsoft\VisualStudio\11.0\ComponentModelCache
https://connect.microsoft.com/VisualStudio/feedback/details/800087/getting-error-microsoft-visualstudio-editor-implementation-editorpackage-package-did-not-load-correctly
