“Value does not fall within the expected range” when trying to add a reference in a project

Question

Suddenly I am getting this error \"Value does not fall within the expected range\" whenever I try to add a reference to any project. This also happens with a new blank proje

Answer 1

Some projects (e.g. some web services) require that Visual Studio be run as an administrator. After a Visual Studio upgrade, I hadn't noticed that it was no longer being started with elevated privileges automatically. When I corrected this, all the projects in the solution loaded.