This problem occurs when PP can no longer 'read' the codec used in the file. Maybe you have a QuickTime issue?
Was the media intitially folder dependent (like AVCHD, P2, etc...)? If so, did you import the parent folder or just the media from within the video folder?
I've found cases where it's throwing that error on things like Proxy (mp4) or Icon (bmp) files during relink, which can just be skipped. So if that's the case, just offline or skip those and you should be ok. However, I've found other' less explicable cases, where relink jsut doesn't like the codec for a particular file, and for that I have no workaround at this time. You would need to re-import it and try to re-edit it in to match the original. Not too bad if it's just one or two files, but if its dozens or hundreds or more, practically impossible.
I'll upadet bac here agin if/when I come up for a solid workaround for that second case... but hopefully it's just the first case for you.
In this case I found out the issue was with quicktime so I just uninstalled then reinstalled and it was working just fine.
Thanks once again.