I have experienced this several times since the last update. It never happened before then.
I am grinding monos, and after a hour or two, warpath magically stops doing damage. My only options are dying, or preferably, portaling out. I then have to exit the game completely - because often just logging back in or trying the same mono again results in a continuation of the zero damage bug.
In this specific player log, the warpath zero-damage bug happens at the very end of the log.
Player.log (3.1 MB)