In the recent update of GenyMotion (Android Emulator) there’s a change which breaks its compatibility with Titanium Studio. You’ll need to open Terminal and create a symlink to fix it, start by opening Terminal and running:
and then type:
ln -s player.app/Contents/MacOS/player
Shut Titanium Studio and GenyMotion both down and then restart Titanium Studio and it should work as usual after that point.