Try to disable your fightclass/plugins and reactive one by one to check if problem is caused by one of this file.
In TBC with simple Fightclass (without plugin): (up to 2/3% of UC in fight)
Follow this guide https://wrobot.eu/forums/topic/1381-repairinstall-wrobot/#comment-966 you need to run WRobot in window mode, and try to use "Automaton" to start
Hello, try https://wrobot.eu/bugtracker/update-buggy-r764/#comment-4045 if your problem is not resolved can you share your log file please ( https://wrobot.eu/forums/topic/1779-how-to-post-your-log-file-with-your-topic/ ).