ID:1997670
 
Okay, so, i opened the game (Colonial Marines Server) and i pressed the ready button, the game crashed, then i tried to open the game again (Same server), crashed, tried to join later, crashed, tried another server, crashed,cleared the cache, crashed, re-installed byond, tried again, crashed, installed an older version of byond, crashed

So, i cant really play the game because i cant even join
Check your Avast settings, try enabling an exception for BYOND. Currently Avast has an issue with BYOND, if this was your problem, please do try to contact Avast to get them to sort the issue out!
In response to Rushnut
I indeed have avast, tried to enable exception, didn't work, then i disabled the avast, didn't work too.
Maybe you can post some screenshots of what you're doing step by step, so other users who've solved this problem can help you through it.
Well, i dont know how but it fixed itself, well...