Having trouble migrating from Windows to Mac

I'm having trouble migrating from Windows to Mac using 13.4 on a new Apple Mac M2 Studio. I can read in the catalog just fine, it updates it to the new format for 13.4.  To update the path to where I've stored the pictures on the Mac, I right click on the folder on the left side of the "Library" module, and choose where the photos now reside on my Mac (they're on a external disk). I get Lightroom error "Internal error has occurred. Invalid path."

I've tried reading the catalog on a Windows laptop, and updating the path in Windows to a local directory on the laptop, the copying it to the Mac and trying again, something that was recommended by the following thread:   https://community.adobe.com/t5/lightroom-classic-discussions/lrc-will-not-open-a-catalogue/td-p/14720962

But I did the entire procedure on the Windows laptop in 13.4, since I don't know how to revert to version 12.  It didn't work, with a different error - the Mac got into a seemingly infinite loop of writing a rewriting the ancillary files associated with the catalog file, along with the spinning beach ball. I allowed this to run for about 15 minutes before killing it.  Did I stop this too quickly?  The catalog file is large (about 1 Gbyte).

Does anyone have any ideas, other than to migrate to a competitor's product? :^)

[Moved from ‘Bugs’ to ‘Discussions’ by moderator, according to forum rules. A ‘bug’ is not just another word for any problem with software!]