Can confirm that I've also experienced this crash. I was also able to cause it by buying Rescue Beam, where the game would crash once I tried to assign the active ability to a key.
Gonna add to this. Frenzy activates like normal when you hit 40% health or lower, but if you heal back over 40% you seem to retain the buffs for a few seconds. Wasn't sure if this was a bug or feature.
