First off, I am not tech support so don't blast me if I cant help you. But, I have been using ofollow ever since it came out. I use it daily... literally thousands of BG's --- and even in TRASHRAN.
HINT - in Ashran, and Deepwind gorge oFollow will only work in "/of debug" mode.
When you say it crashes your clients, do you mean your WOW clients? And if so, when does it crash them? Once you are in game? Or as soon as you get the game up. IF I can help you I will.