Please follow the steps:
1. Play any song from an album
2. Stop playing
3. From Library in Music Explorer, MOVE (right click) the album (or even the artist folder) to some other place
I get a notification from OS that the file is in use.
Retrying doesn't help.
Clicking in Cancel results that the database now point to the new place, but the files were not moved at all.
The file stays locked, preventing that the folder be manually moved.
I have to close HMM12 to get the file unlocked.
Then I can move the folder.