I temporarily place my raw files into a dedicated working folder then file them away by date (along with their sidecar files) after processing in darktable.
I recently returned to edit some images from last year, and imported them directly from their storage folder.
I cannot now remove that folder from Lighttable’s import, add to library view.
If I right click it, a pop-up appears saying “you cannot delete the selected place”.
I have tried closing darktable, deleting library.db and all of the backup library files, then restarting darktable after a reboot, but the problem continues.
Sorry, I thought you meant something else. This I don’t know. I just tried without problems, so unless it’s what Kofa says beneath here, I don’t know. Sorry for the noise.
deleting backups of debases isn’t a good idea if something isn’t working properly - you just ensure, you‘ll need start from scratch if you mess up stuff with your recent one …