The track's in your collection but won't load, or there's an exclamation mark next to it. rekordbox hasn't lost your music — it's lost the path to it. Repair the link and every cue, loop and grid comes straight back.
rekordbox stores a path like /Music/DJ/track.mp3. Move, rename or delete anything in that chain — or plug an external drive in with a changed name — and the link dies. The analysis, cues and beatgrids are all still safe in the database.
File → Library → Display All Missing Files. That's your damage report — everything with a broken path in one window.
Right-click a missing track → Relocate, and point it at the file's new home. rekordbox re-links it — cues intact.
After one manual relocate, rekordbox offers to search the same folder for the other missing files. If you moved a whole folder, this fixes hundreds in one pass.
Keep all music in ONE parent folder and move it with rekordbox open (drag inside the app), never behind its back in Finder/Explorer. External drive: never rename it — the drive name is part of every path.
A DJ library is two things — the audio files, and a database describing them. They're only connected by file paths. Every 'my library vanished' panic is really a path problem, and paths are repairable in minutes.
Fixed it? The manual this came from covers the rekordbox the same way — every control, every failure mode, in plain English with diagrams. CDJ-3000 — The Complete Visual Guide — £9, instant PDF.
Get the manual → £9 Or keep using the free stuff →