"Type Mismatch" error

Hi all -

After several weeks of intermmitently working on a project, opening MM2
scores of times w/no prob, suddenly I get the above message at startup and
the timeline will not load - searched for info, but found nothing.

All clips are .avi or .wmv, all audio is .wav.

Anyone have this experience before?

ANY help will be much appreciated!
TIA!