Hey there, we can certainly get things fixed for you - but before we get going, please don't open/close rekordbox!
Go to this folder:
Win 7/8/10: C:\Users\yourusername\AppData\Roaming\Pioneer\rekordbox
OSX: /Users/yourusername/Library/Pioneer/rekordbox
...and copy these files:
datafile.edb, datafile.backup.edb, datafile.backup2.edb,datafile.backup3.edb
...to a safe place (not in that folder).
Now we have a backup, let's figure out why your music is missing!
- Where was it located? Internal / external drive?
- Was it managed by iTunes at all?
- Have you moved or deleted the files anywhere?
