syncing photos shows 8 mov files as not displayable on iPhone

To rebuild ("repair") the library launch it with the Option+Command keys held down:

Allright, I seem to have located the corrupt movie files and exported those with Quicktime. After adding those new files again - with adjusted dates, those are now syncing correctly and visible on my iPhone. Great to have fixed this finally.

every time the sync process displays info about some eight .mov files which would not show on the iPhone and therefore would not be copied. For each file I have to acknowledge the fact, before the syncing continues.

I can produce a text file with the names of the .mov files. But none of these files seem to exist anymore in my photos library.

What kind of names does the error report? Anything like DC143524-75DD-4AE7-BF7B-518EE89E8FF5?

Syncing to my old iPad Pro had the following kind of errors with HDR/HLG footage that was not supported (my new iPad Air has no trouble with that). For a while also 4K HEVC (4K AVC OK) and silent movies (later macOS update fixed that) produced this kind of sync errors:

“DC143524-75DD-4AE7-BF7B-518EE89E8FF5.mov” was not copied to the iPad “iPad Pro 2016” because it cannot be played on this iPad.

Some videos were not copied to the iPad “iPad Pro 2016” because they cannot be played on this iPad.

That filename was the internal database name which was not very helpful.

I could identify the offending movie via the Terminal:

find . -name DC143524-75DD-4AE7-BF7B-518EE89E8FF5.mov

...so that movie was at:

./Photos Library.photoslibrary/originals/D/DC143524-75DD-4AE7-BF7B-518EE89E8FF5.mov

...and could be opened for viewing with (use quotes to escape spaces in the path):

open './Photos Library.photoslibrary/originals/D/DC143524-75DD-4AE7-BF7B-518EE89E8FF5.mov'

But does the rebuild / repair library suggestion fix the error for Glanz? I have a similar approach and it has been a thing I could not resolve for years. It were 5 mov files before, now it are 6 mov files.

Would be great to have this fixed.

It seems like a sync attempt takes a low of time: it tries to sync every video file again it are ±872 on my mac and that takes a while.

Thank you for the update and quick reply. I'll try that right away.