Success!!

Taking a tip from FranticBlue, I found an old hard drive that still had the operating system intact and was able to find the missing registry entries. This worked for me, and I once again have access to "Add From Discogs." Note that this involves editing the Windows registry, so don't attempt unless you know what you are doing.

In regedit, go to:

HKEY_CURRENT_USER\Software\Firetongue\Organizer\Di scogs

Add string:

AccessSecret

Value data:

JSTYjBuAGdwpMmhITpHZnyZqifpSTbcdgHqDApsr

Add string:

AccessToken

Value data:

FPisAqRyvZMgyPsKHiSioNcwJjdfbBpbvWztwUAQ

Close regedit and see if it worked.