Video Crash/Not Playing

[Sorceror]

I was watching a typical avi file in VLC on my Mint KDE PC for the millionth time and suddenly the PC crashed, although instead of rebooting it just went straight back to the login screen.
Since then I can't play videos of any type in VLC or Gnome Player at all. They just open to the first frame and do nothing.
I've tried disabling the ATI/AMD proprietary graphics driver to see if something there was causing it, but that hasn't fixed anything at all.