And another 'follow up' ... IF course cannot be used by students and if can you make a backup of the course. In the backup process - no users - select only the labels you can not edit. The backup file name will have '-nu-' in it's file name, but you might add '-labelsonly-' so you won't confuse any backups you might have stored locally.
Attach here in forums or send me a private message here with a url where I could acquire the .mbz file (the backup) and inspect it.
OR another larger alt ... if you can backup and restore courses ... make a full backup of the course with users but minus the label resources and restore it to your server by a slightly different name - not overwriting the original course. This only if the original course is currently un-usable.
Could check out the restored course, and if working as expected, then hide the other ... after changing it's name/shortname to 'Something broken' ... and rename the restored course the same as the old (so students can find it).
'SoS', Ken