Migrating LRC catalog to Apple

I copied my catalog from my old Win 10 computer to a new Lightroom subdir (replacing the subdir that was set up when LRC was installed) on my new Macbook/Monterey laptop, signed into LR and tried to open the catalog.  I get:

"Lightroom cannot create a catalog named “Lightroom Catalog-2-2-v10” on volume “Macintosh HD” because Lightroom cannot save changes to this location."

and

"Lightroom Catalogs can not be opened on network volumes, removable storage, or read only volumes."

I have full permissions on all these folders.  Why does LRC think I'm on a read-only volume? Is the Lrcat.lock file involved?