unspecified error occurred. please check the logs for more information

Dear PBE Team... whether this is serious or not, I tried to install LOL NA from my iMac, but when during the process there was a problem when installing. I've tried a fresh install my mac OS and application that I installed the first time is LOL, but the same problem occurs. I can beg a little enlightenment and solution of the problems I experienced and probably others who experience the same problem. This is my imac spec :

• iMac
• 21.5-inch, Mid 2010
• Processor 3.06 GHz Intel Core i3
• Memory 4 GB 1333 MHz DDR3
• Graphics ATI Radeon HD 4670 256 MB
• Software OS X 10.8.5 (12F45)

Thank you guys :)

regards