OK, I've not worked out what it is yet, but it would appear to be something in the IPTC block that's triggering the photoshop warning.
I used XnView to remove a tag block at a time from a copy of the image above, starting with xmp, and the error persisted until the IPTC block got removed.
If I then update tags from library, an IPTC block is written by MC, and there's no complaint when subsequently opening in photoshop. Note that simply running "update tags from library" on the 'bad' file does not fix it.
Also, I'm working backwards in time here, cropping (copies of) images to better fit my TV screen and saving gigs of HDD space into the bargain. I have not encountered this error for a while now, leading me to believe that perhaps there was a period where the tags were not being written out correctly, and that that is now fixed? I don't know.
I did a quick google search on the error message + IPTC and found this in the digital machanic forums...
http://forums.camerabits.com/index.php?&topic=3725.msg16890#msg16890For now if you check the preference to "Add Photoshop resolution to Camera JPEGs during IPTC update" (the default) then you won't encounter this problem.
?
I've also taken a new photo straight off this Fuji camera (which incidentally, is the worst I've ever owned!) and tagged it using MC, applying the same keywords and photographer as the 'bad' file above. MC then writes an IPTC tag block, and the image opens in photoshop without a problem, suggesting to me that the problem is an historical one.
Using MC 16.0.180 to change the keywords on the 'bad' file example, updates the IPTC data, and the error goes away.
That'll do for me going forwards. If anyone still wants to chase this one, let me know if you want anything else tested.
-marko.