Friedel Craft 4-methoxybenzophenone polymerization?

I am wondering if anybody has run the Friedel Craft lab with anisole and benzoyl chloride using aluminum chloride as a catalyst to make 4-methoxybenzophenone and had students end up with a red sticky polymer looking substance. I am wondering if there was a polymerization side reaction that occurred due to either too long of a reflux or students using an incorrect amount of one of the reagents.Any thoughts would be appreciated.Thanks,Sonja