I'm using 10.9.5 - and with no obvious changes to major software (updated Firefox and DivX player in last couple of days) can't do more than open Finder before the window disappears. Browser windows not disappearing, nor system preferences, but Finder window just disappears every 5 seconds so can't do more than go to applications and it quits. Message popping up occasionally that window closed unexpectedly - I hit don't reopen - but then it just comes back with the same message. Trying to watch a DVD - it opens but the window disappears (still there but only stays for 5 secs then back to the desktop image (even if DVD playing in background). Have tried force quitting finder, looked through the activity and force quitting those - nothing of use in any other threads (not using Google drive or stuffit) Shutting down or restarting doesn't help Is anyone else having this problem - it's obviously some sort of loop - anyone got a solution?