WowAce

What steps will reproduce the problem?
1. Gather all required things for a quest.
2. Sometimes I get it when I finish a normal quest.
3. I'm not even sure it's QuestInfo's fault, but it's always something quest related that breaks it, and then it's QuestInfo that's broke.   I'll get to a point where all the icons disappear from the map, and if I try and select "Show Active Quests" to get them to come back I get the error as well.

What is the expected output? What do you see instead?
No annoying errors popping up every 30 seconds ;-)

What version of the product are you using?
Latest on Curse.

I'm not seeing this on my patched version.

Maybe the patch I added here fixes it: http://www.wowace.com/addons/cartographer_quest-info/tickets/12-error-after-going-through-a-portal/