Unity3d sometimes freezing during script compilation or after hitting play button

Hello, I'am running Unity3D pro 4.6.2 (I tried 4.6.3 and even some older versions) with Parallels and Visual Studio 2013. It happens quiet often when I edit a script in VS and switch back to Unity, Unity freezes during script compilation. It also sometimes freezes when I just hit Play button (The button doesn't even get blue). I'am sure it has nothing to do with infinite loops (I'am not the only developer on a project) or memory problems (I have 8GB of RAM and memory pressure in Activity Monitor is always green). Any suggestions are highly appreciated, thanks in advance, Jakub