I've been working on this movie project for 5 weeks now. I'm very close to finishing it, but suddenly, while doing some final edits, several of the clips from various videos are suddenly shown as corrupted. I've never touched the source video in any way that would suddenly make the clips corrupted, and they worked perfectly for 5 weeks, so I see no valid reason why they would suddenly become unsupported.

This is extremely frustrating.  Needless to say, I've poured countless hours into it already, and instead of telling me right from the start that there is something wrong with the videos, the movie maker decides to do this when I'm minutes away from completion, and now I'm just stuck. And I'm convinced that this is actually a bug rather than genuine problems with the videos. Because every time I close the movie maker upon getting the corruption warning, and restart it, the videos become good again. And after editing for a while, some different clips are reported to be corrupted (whereas the ones that were shown to be corrupted from before are suddenly OK).

All of my videos are of the exact same format and the error reports are completely random and nonsensical. 

Please, someone tell me that there is a way to fix this or else I would have wasted dozens of hours. So far, restarting the program only makes the issue disappear temporarily as doing further editing will prompt the error warning. 

Thank you!