Visual Studio 2017 enterprise can not add reference

Question

When I want to add a reference in a project in Visual Studio 2017 Enterprise. I get the following error:

"The operation could not be completed"

I have tried cleaning and rebuilding solution, restart computer, delete bin and obj folder and all .suo files. Also there is no error in my Web.config file.

Answer 1

So I got help from microsoft support.

1. Open Visual Studio Command Prompt as administrator
2. Goto the path of your visual studio installation, standard is: C:\Program Files (x86)\Microsoft Visual Studio\2017\
3. Select your installation type and goto \Common7\IDE\PublicAssemblies
4. Run command: gacutil -if Microsoft.VisualStudio.Shell.Interop.8.0.dll
5. Run command gacutil -if Microsoft.VisualStudio.Shell.Interop.11.0.dll

This fixed it for me