Well, I just downloaded the Genkibowl DLC, and the game started fine. I checked out the Team Fortress 2 Hats, but as soon as I wanted to start the genkibowl mission, the game froze. Looks like the new DLC messes with the mission replay mod. Oh well, back to vanilla SR3 then.
Strange, the DLC doesnt show up ingame at all, even though I bought it with the season pass.