In trying to fix another issue, I removed a movie library and replaced it with the same library using a UNC path rather than a local path, then re-scanning the entire library. However, this caused a problem with existing collections made up of titles from the old library. I now cannot see the original collections and when I try to re-create collections for those titles, I get an error stating the collection already exists. I tried editing the collection.xml files in AppData\Roaming\MediaBrowser-Server\data\collections\ to update the local paths to the UNC location, and re-scanning the libraries, but the collections remain missing. In the server log, I get messages stating it cannot locate content for these collections at the old local path (Warn - BaseItem: Unable to find linked item at path M:\My Movies\...). Metadata manager does not show any of the orphaned collections or content either.
If possible, it would be great to be able to restore the original collections, but if that is not possible, I'd be fine with deleting the original orphaned collections and re-adding the titles. Even deleting all collections and starting from scratch would be fine. Any ideas how I might do this?