Maybe the drive is read-only or write-protected? Maybe the folder that contains the catalog file is read-only or write-protected? Maybe you don't have permissions to write in the folder that contains your catalog?
And if those fail, you should restore your catalog file from a recent backup.
Thanks. All involved folders and files have "read and write" privileges.
Have restored recent backup but still would like quick collection. Have a
few days selections contained therein.