I'm fairly new to Ubuntu, so I don't know if this is a simple fix or not. I've read some fixes to answers for my problem but I don't really know how to do any of the things they're telling me to do (such as installing proprietary drivers). I'm having the same problem that UbhiSukhpal posted about, but my attempts at fixing the problem have not been successful. Starting Steam from Terminal hasn't worked either. This is the message I get when I try to do start it from the terminal.
chris@chris-VPCEE41FX:~$ steam
Running Steam on ubuntu 15.04 64-bit
STEAM_RUNTIME is enabled automatically
Installing breakpad exception handler for appid(steam)/version(0)
libGL error: unable to load driver: r600_dri.so
libGL error: driver pointer missing
libGL error: failed to load driver: r600
libGL error: unable to load driver: swrast_dri.so
libGL error: failed to load driver: swrast
Any help would be awesome. I apologize if this is going to be tedious. :p