Unable to complte this quest

[RRedjou]

Uldum
Do the World a Favor

When you complete the quest you are prompted to click on the yellow ? to complete the quest but the yellow ? is never presented. Must turn off Carbonite to clear that quest, then turn Carbonite back on.

Has never worked.

[Sparkplug]

You don't have to turn off Carbonite. If you run into the problem again, hit Alt+L to bring up the default quest window and complete it from there.