QuickTime Player won't save edited file: The operation could not be completed

I've edited an MP4 movie file in Quicktime Player Version 10.5.

When I try to save the edited file, I get: The operation could not be completed.

Does anyone know what causes this and/or how it can be solved?

macOS Mojave 10.14.2 / Quicktime Player 10.5 / MacBook Pro (Retina, 13-inch, Early 2015)

Solution 1:

I had a similar problem when I downloaded a youtube video, opened in Quicktime to "trim" the video and quick time would not complete the operation. I ran the youtube video through Vlc Crunch (free video converter)as mp4 again and then Quicktime worked fine.

Solution 2:

Not an actual answer. But inform some important piece of information.

I encounter the same problem. The error code is "-12769"

Found out that there are some input videos which worked.

And when I compare both info of videos.

A video that's work :

A video that's doesn't :

The only difference is encoding software between Lavf57.19.100 vs Lavf58.12.100

Solution 3:

For me, the error came as I was editing in Quick-Time by right-clicking on the imported video in the Photos app.

Once I dragged the video (export) to a directory, and then edited the .mp4 file, all was fine. No errors when Trimming and Saving.