I'm having the same experience. Tried r12678, r12677, and r12676 before looking here. My steps were simply:
1. Open mafia
2. Go to Gear Changer tab to verify current gear state
3. Open maximizer window
4. Enter parameters (in my case: ML, mainstat, spell dmg 25 min, initiative 5 max 0 min) and update
5. Select "equip all" action
For giggles I unequipped everything first on my last try with r12676 to see if that made any difference but it still froze. It seemed to be working that time, but then got stuck on the familiar equip slot. Previous to that attempt it had been freezing after the very first equip slot change. If this turns out to be irrelevant and just confusing to the issue I apologize >_<
