Resolved: Error ‘Microsoft.VisualStudio.Editor.Implementation.EditorPackage’ package did not load correctly.
After installing Visual Studio 2015, I got the dialogue box with error “‘Microsoft.VisualStudio.Editor.Implementation.EditorPackage’ package did not load correctly.” , when I opened the application which is running on Visual Studio 2012. This error can also happen after updating VS 2012. Solution: Close the Visual Studio and then remove the folder “%LOCALAPPDATA%\Microsoft\VisualStudio\11.0\ComponentModelCache” . Once you are done then restart the Visual Studio and it should work fine then.