Workaround found in the Bugzilla: http://bugs.winehq.org/show_bug.cgi?id=24096#c5 It's actually working very fine if you follow the instructions 100% (if you forget to rename the GameOverlayRenderer.dll back to its own file, Steam will just update itself again and it will be included, but it takes time so better rename it back if you shut down Steam) But it is working at least and its possible to play again until we wait for a fix ;]
