Error Message when setting color rating (or changing any info in Metadata)

[cbrownphoto]

Photo Mechanic Version 6.0, build 6097 (85d1687)
Mac OS 11.6

I've been culling in PhotoMechanic files that are on an external Seagate drive with 3 TB available.
I can set the color rating when I am working with files in one folder.
But I get an error message when I try to set the color files in another folder on the same external drive. (I tried changing the caption in metadata on the same files and got the same error message.)

Seems odd that I can set ratings when culling photos in one folder, but not the other. All photos are CR3 photos shot in same camera.

[ahoward]

Is the problem only with this folder? If you delete the XMP file at the location specified in the error message (make sure its just that XMP file and not others that may be present in the folder for now) using Finder and then try to edit the metadata again using Photo Mechanic, do you get the same error? Have you checked the permissions on this folder?