Whole Photo Library Greyed out for import / backup second drive
I'm using Catalina on my late 2013 iMac. When I try open my main library and try to import, the 'Review for Import' window shows that both of the libraries I am trying to import are greyed out.
I have renamed them so is this an issue - I can open both libraries independently on the same computer plus my main library?
BTW my old Segate remote drive where I stored all my photos catastrophically failed and it was unable to be repaired. Fortunately, I had an old backup, so I only lost 2 years, hence I am amalgamating libraries.
Have you any recommendations for backing up a second remote drive in addition to a Time Machine Remote Drive, as I think Time Machine only backs up the main drive?
iMac 21.5″, 10.15