After doing an import of some images and closing Lr, this setting changed to:
AgImport_backupDownloadFolder = "C:\\Documents and Settings\\Tony\\My Documents\\My Pictures\\Lightroom\\Download Backups",
This is now using the old Windows XP folder names ("Documents and Settings", "My Documents" and "My Pictures"), and yes, I know there are hidden links in Windows 7,8,10 to handle these old names for backwards compatibility.
which is obviously related to the AgImport_backupDownloadFolder entry.
In 2020 why is Lr Classic 9.1 doing this?
The initial setting for the folder path was correct. This led me to think Lr was updating it from the catalogue. Further investigation has found that this is the case. It is an entry in the Adobe_variablesTable table and there is another entry with the name SynchronizeFolder_backupDownloadFolder that also has this same folder path using old XP folder names.
In the newly created test catalogue, I found the entry for AgImportDialog_backupDownloadFolder had a value C:\Users\Tony\Pictures\Lightroom\Download Backups, but the entry for SynchronizeFolder_backupDownloadFolder was initialised with the value C:\Documents and Settings\Tony\My Documents\My Pictures\Lightroom\Download Backups
I can understand that an old folder path might be "inherited" when upgrading from an older catalogue. I would have thought the newly created catalogue would always use the Windows 7,8,10 folder names in folder paths, but it doesn't.
I would also have thought that the migration of catalogues from older Lr versions to Lr 7,8,9 would have updated these records to use the current Windows folder names.
I wonder how many other old XP styled folder paths are in the catalogue?
I also wonder what these entries are for? The folder path they refer to doesn't exist on my system!
You might say it isn't a real problem since the OS handles it, but it shouldn't be there in 2020.