I installed steam on Ubuntu Mate 15.10, and i cannot open it. I opened system monitor and I saw steam running, so i closed it and I reopened it and nothing. Its status is sleeping if that helps. I opened it in terminal and heres the output.
Running Steam on ubuntu 15.10 64-bit STEAM_RUNTIME is enabled automatically Installing breakpad exception handler for appid(steam)/version(0) libGL error: unable to load driver: nouveau_dri.so libGL error: driver pointer missing libGL error: failed to load driver: nouveau libGL error: unable to load driver: swrast_dri.so libGL error: failed to load driver: swrast