Repeated Game Crash/Bug splat

Randomly, my game will just crash during the game. No lag spike, no issue of any kind. I will be playing and everything will be going perfect then it just ends and I get a report issue. Half the time bug splat doesn't pop up and other times it does pop up but bug splat also crashes and I have to force quit bug splat.

I play on a mac circa 2014. Started happening a couple months ago. Doesn't matter if I redownload the game or anything. Need a fix please!

here is the report: Process: LeagueofLegends [689] Path: /Applications/League of Legends.app/Contents/LoL/RADS/solutions/lol_game_client_sln/releases/0.0.1.28/deploy/LeagueOfLegends.app/Contents/MacOS/LeagueofLegends Identifier: com.riotgames.LeagueofLegends.GameClient Version: 1.0 (1) Code Type: X86 (Native) Parent Process: LeagueClient [509] Responsible: LeagueofLegends [689] User ID: 501

Date/Time: 2018-02-26 11:49:00.240 -0500 OS Version: Mac OS X 10.13.3 (17D102) Report Version: 12 Anonymous UUID: 66D49F00-DF6D-C27D-8431-178115AE52A4

Time Awake Since Boot: 1900 seconds

System Integrity Protection: enabled

Crashed Thread: 14 Dispatch queue: OpenGLMT

Exception Type: EXC_CRASH (SIGABRT) Exception Codes: 0x0000000000000000, 0x0000000000000000 Exception Note: EXC_CORPSE_NOTIFY

Application Specific Information: abort() called

Application Specific Signatures: Graphics kernel error: 0xfffffffb