I suddenly couldn't attack or cast spells, except with my throwing knife. This happened in the middle of a boss fight in a Boss Rush realm, at power level 140 against Sheliak.
I tried rebinding my attack key, turning my mouse on and off, and plugging in a wired Xbox controller. I died before I could find a different mouse. My gear wasn't broken.
All other controls worked fine. I could do everything except attack.
After I eventually died while trying to find a different mouse, I was able to attack again.
