Xamarin.Android is stuck in activation loop

I can't activate Xamarin.Android. My Visual Studio 2012 is stuck in activation loop. I get an activation dialog, then it wants to restart Visual Studio. Once restarted, I get exact same dialog again, and it wants to restart again.

I didn't find any topics on similar problems with activation of Xamarin.Android, but there's a topic describing an exact same issue that I am having but with Xamarin.iOS: http://forums.xamarin.com/discussion/comment/6622/#Comment_6622

Any suggestions? Thanks