Every time I download the game (Mac version) and open the .dmg file and drag it to the applications folder, I get an error saying "TheWalkingDead is damaged and can't be opened. You should move it to the trash." I've redownloaded four different times even making sure nothing else is running and I still get the error. I've got OSX 10.8.3 which is above the requirements and plenty of space. Anyone know what's up?