Gmod mac loading error?

I just got it today. It worked perfect the first time and loaded quite fast with no lag in game. Then I tried to exit it to check something and used the escape key, it quit with an error report. Since when i try to load it I get a never ending loading screen and I'm stuck with the beach ball loading cursor... It said something about the engine in a seperate window with a Steam api error but I'm not sure if this helps.