Board Thread:Questions and Answers/@comment-77.42.129.118-20160304140458/@comment-26200925-20160304161843

Restart the game a couple of times; if this doesn't work, verify the integrity of the game cache; if this doesn't work, reinstall graphics and sound drivers; if this doesn't work, reinstall the game; if this doesn't work, report the issue to the developers on the official forums.