Running LoL on guest account on mac
Solution 1:
I am assuming you are getting the same error that I got when trying to launch the LoL client as a different user than who installed it. The error is something along the lines of: "You do not have permission to launch League of Legends" or "This application cannot be opened".
I was able to get League to launch as any user logged into the computer. We are in a Windows domain environment where different users login to our lab iMacs.
You can do this by opening Terminal and running the following commands:
cd /Applications
sudo chmod -R 777 "League of Legends.app"
The above commands set file permissions using the CHMOD command on the "League of Legends.app" package and any files/folders below it (-R). The command allow everyone to read and write as well as open/execute the application (777).
Hope this helps!
Solution 2:
This exact problem happens to me every once in awhile. I think its a Mac specific bug. Try doing a PRAM reset (restart your mac and hold ⌘ + ⌥ + P + R while it boots up).
Apple documentation on how to PRAM reset: http://support.apple.com/kb/ph4405
Then open LoL, and give it a good minute to start up, and make sure not to touch anything else on the computer until it gets past the logo. If you've waited a minute and nothing has happened after the logo showing, open it again when it tells you another instance is already running, press yes to cancel the old instance and open a new instance.
If this doesn't work I would recommend reinstalling the LoL client.