title: Productivity Power Tools for Visual Studio is disabled and won't enable
body: <p>I had Productivity Power Tools (PPT) installed on my Visual Studio 2012 for quite some time and everything was working well. Suddenly, it stopped working and I noticed it got disabled under Extensions.</p>
  
  <p>I cannot enable it (the Enable button is grayed out), only uninstall, but even uninstalling it and re-installing it didn't do the trick!</p>
  
  <p>I also installed VS 2013 Community (the new full free version) and installed PPT on it and the situation is exactly the same.</p>