Upgraded Lightroom Classic to Catalina based Catalog Won't run on Monterey M1 Powerbook

[thomasd78476151]

I was having no issue using any of my external harddrives with Lightroom Classic catalogs on any computer.  High Sierra-based versions I was using on my 2019 iMac which I was also using on my new M1 chip Powerbook I got in Dec 2021.  When I upgraded my iMac to Catalina - now when I go to use my external harddrive with Lightroom Classic it says the catalog is newer than the computer I am on and won't work.  However, Monterey is a newer OS by a few versions.  It has now hog-tied me and I can't travel with my Lightroom catalogs... big help please!

[dj_paige]

Please tell us the exact word-for-word error message, verbatim.

The error message may be referring to Lightroom Classic versions. What version NUMBER of Lightroom Classic is on each computer? But that's a guess, and that's why we really need to see the exact word-for-word error message.

[JohanElzenga]

The error message almost certainly has nothing to do with the MacOS versions of the computers, but with the versions of Lightroom Classic. You upgraded Lightroom Classic on one computer -and so your catalog was upgraded- but you did not upgrade Lightroom Classic on the other computer. And so the catalog version is now newer than the Lightroom Classic version that is running on that computer. Make sure you use the same version of Lightroom Classic on both computers!

[thomasd78476151 · Accepted solution]

Thank you for your replies, it is very much appreciated.  In following your request to find out the version numbers, the problem & solution slammed me in the face.  Face-plant time:  while my new computer does have a more recent OS version, contrary to what I recall and have needed - it did not have Lightroom loaded onto it yet!  I'm not sure how that is possible but there it is.  Professional face-plant!  I was using Photoshop and must have blended them together in my brain.  All-in-all... happy to have it all functioning!  Thank you again for pointing me to the very core of the problem!