Unable to start tf2 on Mac

[oscar]

After installing the new update,when i try to start up tf2,my tf2 crashs. Heres the terminal commands
/Users/student/Library/Application\ Support/Steam/SteamApps/common/Team\ Fortress\ 2/hl2_osx ; exit;
Killed: 9
logout

Could someone help me?
I have already tried restarting