QuickTime refusing most of my .mov files

I'm experiencing a strange phenomenon where most video apps on my Mac — including QuickTime — refuse to open perfectly-good .mov files. These QT movie files are actually output from FCP (probably a mix of 7 and X) and used to open just fine... they're full-res saved exports of completed project timelines, and now that I want to use excerpts from them in a new video, I can't open them at all! Not even the quick-view method of just highlighting their icons and hitting SPACE to preview them.

In a folder containing 64 QT movies, maybe 2/3 of them will not open now. They were created between May, 2016 and March, 2017 so none of them are old enough to blame their age on them not working, especially since I haven't updated my MacOS in that time.

For what it's worth, those that can't open show no useful info in iMediaHUD. Those that I can open (with the quick-view method or in an app) give full info in iMediaHUD.

Any ideas?

— Mike

Probably saved as reference movies, the data is elsewhere, probably lost.

Cheers
Alexander

Hey Mike
How big is each file, use "Get Info".
If the file size seems right, try a different player like VLC to open and view. If they do play, then it is some form of data corruption in the directory. You might then try to copy to another drive or use a file conversion app to try to re-establish the correct data tree. You could also use Terminal if you are comfortable with it for adding needed permissions and data.

If on the other hand, if Get Info shows very small file sizes, then you most likely just have aliases or references. Your error pop-up indicates this might be the case of no attached media. Look on old drives for the media and complete file.

You don't give info on OS version, and FCP versions. This can mean a lot for recovering files and library structures.

Hope This Helps, Greg

Do they open in Final Cut?