I have experience the same issue with Visual Studio 2013 Express for desktop
and all projects could not be opened but the projects are shown like "Tweetinvi(imcompatible)" in solution explorer.
And I installed VS community edition and It allows me to open all of projects.
Now I can open projects and those are shown like "Tweetinvi(Portable)" !
and all projects could not be opened but the projects are shown like "Tweetinvi(imcompatible)" in solution explorer.
And I installed VS community edition and It allows me to open all of projects.
Now I can open projects and those are shown like "Tweetinvi(Portable)" !