I faced today a new issue with Visual Studio when trying to add a refence to one of my projects in the same solution.
I checked the build status, everything built properly without issue, however, whenever I tried to add a reference I got an error message saying that “The operation could not be completed.”
1- Run the Developer Command Prompt for VS 2017
2- Browse to
C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\Common7\IDE\PublicAssemblies
3- Register the following assembly to the GAC
gacutil -i Microsoft.VisualStudio.Shell.Interop.11.0.dll
4- Restart Visual Studio IDE
5- Tadaaa !!!