Sometimes questions get asked, then the need for them to be answered goes away before the question is answered. Answering the question would be a matter of a some kind of post-mortem examination, but the problem is gone and the original asker has no interest in solving it.
I've meant to ask this before, but a new example just cropped up with this question. Since nobody can replicate the problem and the original asker no longer has the problem, requests for more information to provide a definitive answer are useless. It's likely the problem isn't accurately described, but difficult to correct.
Should a "cop out" answer such as "update your system" be provided so that the question can be marked as answered? Should the question be closed? Should it just be ignored and left for time to bury unless somebody else with the same problem comes along and resurrects it with more info?