League will not open on Mac

Following the most recent update, I went to open league on my mid 2011 iMac. It opened and showed that the update completed. However, after it updated it closed itself out and wouldn't let me reopen it at all. It would bounce on the task bar then close again. So I deleted it to try again but the exact same thing happened. I've cleared my cache and force restarted my computer, but nothing will work. I faced a similar problem a few months ago when URF was rereleased on the PBE. It would open the client then close itself before anything could happen. Do you have any suggestions, or is it a bug that is out of my control? Also, will I be reimbursed for the 10th anniversary prizes that I miss since the problem seems to be out of my control? Thanks for the help!