Minecraft is crashing after a certain amount of playtime

I'm on a realms server and after playing for a while, although the time played varies, the game goes to a faded white and crashes with the code "Process crashed with exit code -805306369". not sure its a bug or what, but I can't seem to find a lot of information on this code. I also should state that I have optifine installed, but it never gave me problems before. The launcher also says it has exit code 0 after the game crashes.