What do you think of updating OS X to 10.9.3/4? Those were pretty safe updates.

P.S. It worked before because there were no intro videos. You can btw delete them from Localization folder in Steam but let's keep it as last resort

P.P.S Can you try rebooting Mac just in case

Last edited by Stauff1138; 30/06/14 11:11 PM.