Hi Kirk, I was away, I simply loaded it up after I returned and found no catalog in place. I had no issues prior to departing. The catalog loaded and worked perfectly.
I worked out (sorry newbie to PM) where the catalog management feature was and attempted to locate it, but that threw up the error message.
I could start again, I'd been focussed on getting the majority of my existing work in there rather than much tagging or rating. And my intention for the catalog was for completed work and their archival use. The proxies folder is about 43Gb so quite large perhaps.