I have a question for which I posted a bounty, and, at the end of the allotted time, all answers had score 0. Rightfully, too, as, to this day, no one actually answered the question.
No question was marked as accepted -- thankfully! -- but I can't accept any answer anymore. I also can't open a new bounty on it. Honestly, I don't mind losing the reputation on the bounty permanently, but I do mind not even ever being able to have an accepted answer to my question!
I understand being able to reopen bounty on questions can lead to exploits, but in a case where NO answer was accepted at all, this just doesn't seem to be the correct behavior.