First joined an automatched game
Heard sound effect for starting a game, game doesn't actually start
Reloaded, it attempted to rejoin the game, and also saw "Internal Error" in the corner of the screen.
Reloaded a few more times, picking "Return to Lobby". Attempted to join another automatched game, got a "You are already in a game" error
Reloaded again, see the Table screen
At around the time you posted there seems to have been some kind of problem, I and my opponent had similar problems with apparently being already in games but not being able to 'get to them'. I assume something irregular happened with the server switch at 21:00h CEST (10 min before your posting).