Visual Studio error "Object reference not set to an instance of an object" after install of ASP.NET and Web Tools 2015

Maybe this helps:

1. Delete the contents from the following folders:
   1. C:\Users\%userprofile%\AppData\Local\Microsoft\VisualStudio
   2. C:\Users\%userprofile%\AppData\Local\Microsoft\VSCommon
2. Sometimes, you need to go to:
   1. [x64] C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE
   2. [x86] C:\Program Files\Microsoft Visual Studio 14.0\Common7\IDE

and run devenv /resetuserdata.

Expect, that all of your user settings such as Visual Studio layout, linked Microsoft account or start page might disappear.

Delete %LocalAppData%\Microsoft\VisualStudio\14.0\ComponentModelCache and restart Visual Studio.

Alternatively, use the Clear MEF Component Cache extension.

For me,

1. I ended the process in Windows Task Manager: VsHub.exe.
2. Restarted Visual Studio.

After that, everything works like a charm again!