AAE Error when importing PT (WAV or AIF)audio filess

When I import an audio file into a new session from the desktop or jump drive, I can see the file in the edit window, but if I try to do anything with the file (like use space bar to play, or even just try to click on the imported file), I get the error message (AAE ERROR 6) at which time PT will not let me proceed with the session. I can easily import an audio file from the working directory for Pro Tools and it works fine, but if I copy one of these files to the desktop and then try to import back in from the desktop, I get the same error message and can do nothing with the file (although the file appears to have imported into the session). Has anyone had an issue with this? I have Pro Tools 11 running on a new Dell 8700 desktop with 8 Gb RAM, i7 dual core 3.8 Ghz processor, Windows 8, 1 Tb HD, M-Box 2 Pro with Firewire 400. Haven’t tried any real troubleshooting because 1) I’m in the end stages of finishing up a CD and fear screwing something up, and 2) really have no clue where to begin in terms of trouble shooting. Except for this glitch, everything is working great with no other issues or errors for the past 400+ hours of use on a new Protools 11 install. Any thoughts would be greatly appreciated.