Hiya! You should generally use the search button to look around for previous threads on the problem, to avoid duplicates :}
The error-on-quit issue has been known forever, but as it doesn't interfere with the gameplay itself a fix has been put on the backburner as more important things are taken care of first. If this pop-up is really irritating (as it is to me), try quitting PS through the task manager, if you're on Windows.
