Screetch, do you have the
Community Pack installed? My guess is that you don't at the moment, and that installing it would get you up and running while I do a proper fix. It seems I accidentally created a dependency on that package. I'm going to be fixing that ASAP, because while the Community Pack is excellent and I recommend it to everyone, I don't want it to be a requirement for SoM to work.
EDIT: Yep, I'm running into a few more of these as I go.