Any free solutions that work well for MP4 file repairs? I'm aware there are paid softwares for this, but asking about legit free solutions.

After 6 years in video I FINALLY got one corrupted clip. It was important to me as the filmmaker to recover it, but I could have edited around it if it came to that. Another desparate option was to 4k RE-FILM IT from my computer monitor as it played back fine in VLC, but no where else, nor in VEGAS 15.

In the end, I was able to make multi passes in VLC convert and ended up with usable video, and separate audio that I easily GROUPED in Vegas just fine.

So, I got it covered. But, what do you guys use to fix files?