Crashing on multiplayer MAC Computer PLEASE HELP

Hello, MAC has just recently received updated software Sept. 24, 2014, if I am correct. That is the day I updated my computer. I have the feeling that may be the reason why I keep crashing on multiplayer because I have done many things to try and fix my problem. I have deleted the game twice with all of it’s local content and addons, and reinstalled each time, but multiplayer is still crashing. Here is what is happening; every time I start the game it is perfectly fine and I can play on single player for as long as I wish, but when I try to join a server everything will load and be fine until the server actually opens and I can start playing. As soon as I get in I crash, and sometimes while everything is loading I crash. An error message shows up saying the app closed unexpectedly. Everything was working perfectly fine before this software update so I really believe that is the problem. How do I fix this? I paid money for this game and I love it. I just want the issue resolved.
Thanks!,
Ayebby1234

Solution: Get Windows.