I’ve had a consistent problem when selecting multiple already converted images and then bringing up NLP (to use match or sync typically). Immediately upon opening NLP the non-primary image gets a little red exclamation point, which when clicked on says “Lightroom has encountered a problem reading this photo.” From that point on, changes to the image from NLP do not reflect, and I have to restart Lightroom to get the error to go away.
From my troubleshooting, it seems like this primarily happens when I am in a view other that Grid, especially when I am in Loupe view. Attached are two screenshots showing what is happening.
The Loupe-view detail you mention is worth narrowing down first, since it points more toward how Lightroom is reading the second file than to NLP itself. Before resetting in the first tab, try switching those images to Grid view, confirm they render cleanly, then open NLP and see if the exclamation mark still appears. If it does, comparing a folder where it fails against one that works could reveal a permissions difference. Your screenshots seem to show the error happening right at import handling rather than conversion, so isolating that step may save a redo.
I don’t think its a permissions error, as it happens periodically, not all the time, as well as in both local folders and external drives. It occurs after conversion, not on import, when I’m going back to make more edits.
Typically I invert a whole roll, then work through and tweak to my liking. A lot of times I’ll want to use “match” on similar shots that NLP has inverted slightly differently, and that’s typically when I experience this is as soon as I open the NLP window with more than one image selected.
I was incorrect about the Loupe view too, as I have now had it happen in Grid view as well. However, I have been having success with this workflow while Develop is open, so maybe it has to do with the previews Lightroom generates. I also found through some more investigating that even when an image is erroring, NLP is still correctly applying the edits, as they are visible when I toggle to Develop.
So, I have a workaround I guess, but it is still weird and a bit annoying that it errors out in the other workflows.
