The problem started when I plugged in an additional external USB drive. The drive I use for my photos was labeled F:, now is labeled G:, even after removing the additional drive from the system. The catalog in LIghtroom still points to F:, which currently doesn't 'exist'. The physical drive is fine - Windows explorer sees all the files. I see two approaches to solving this, neither one of which I know how to do: (1) reassign the letter F; to the drive (2) repoint the catalog to G:.
Any and all input welcome!
Those are the two choices.
To change the drive letter, go to Google and type in
change drive letter Windows
To change where Lightroom finds the photos, see Adobe Lightroom - Find moved or missing files and folders
Thank you for the fast reply - I'll give that a try!
That worked like a charm - many thanks!