Did the upgrade and had the:
"The libraries these files belong to have been deleted. A new library may have been created with the same path, but the ID of the library has changed.
To process these files, delete them and scan the library again."
Warning, now wants to reprocess an increasing large number of files, currently at 800 out of 10,000.
nb. Did a full image backup this morning, so I can restore to before the upgrade.
System Logs attached