Lightroom cannot save to JPG modified by exiftool

[boldstripe]

This problem just turned up for me on Lightroom Classic 12.3 with some 10-year-old TIFF files of prints made on an Epson scanner with Silverfast.

The fix for me was turning on 'Automatically write changes into XMP' which seems to do something different from the menu command 'write metadata to file'.

I had tried saving/reading metadata in several ways and used the exiftool analysis to try and find a difference between very similar TIFFs that were saveable or not saveable but had the same origin. I could not identify any bad tags or any differences in working/non-working TIFFs.

I had resorted to stripping the XMP completely from some of the files, which 'works' at the expense of any Develop settings etc.

I then noticed that the Catalog Settings...> Metadata panel did not have 'Automatically write changes into XMP' checked, which historically I have done. Simply checking that box made every 'down arrow' on hundreds of files disappear with no further action, and editing the files then proceeded normally also without new 'down arrows'.

Presumably this hinges on some difference between the Lightroom menu command 'Save Metadata to file' and setting 'auto-writing of metadata into XMP' checkbox.

I took this opportunity to convert the TIFFS into DNGs.

FYI: Lightroom database on Mac Mini 2018 i7 32GB RAM running MacOS Ventura 13.3.1, Lightroom Classic 12.3, image files stored on a TrueNAS SMB server accessed over wired Ethernet local network.

[Phil Harvey]

The Adobe XMP parser isn't very robust.  I've seen it fail on perfectly good XMP in the past, and when it does the Adobe software may fail to load the image.  But they will fix the problems if you can isolate them and report them.

- Phil

[boldstripe]

Thanks. Oh, and even when LR said it could not save the metadata to the files and showed a 'down arrow' in the corner of the image's grid view, actually running exiftool on the file I could see that any changes in metadata (key words, description etc) were getting saved by the command 'save metadata to file'.