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)

  • I have the same problem. Found out later the error code is "-12769". – b.ben May 4 '19 at 5:36

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 :

Good video

A video that's doesn't :

Bad video

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


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.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .