Hmmm. I've had a few crashes on level loads as well. After ctrl-alt-deleting your way back to the desktop you can see an error for missing or invalid files and an instruction to revalidate your steam files. I've done that but the problem is reoccurring. Definitely a bit rough around the edges currently it seems!
If the internet profile has come in at the expense of customisable local deathmatch teams then they have made a big mistake! All my worms fun to date has been with friends and family, face to face; I've never played an internet game.