THE PLAYER SAYS
USB FULL

AlphaTheta list USB FULL beside the E-codes for the CDJ-3000 and CDJ-3000X, and the cause is one sentence: "Recording and saving of cue points are disabled due to lack of free space on the USB Storage Device." The tracks still play. What stops is anything the player needs to WRITE: a recording, or a cue or loop you are trying to save.

Read it as "read only", not as "broken". Playback needs no free space. Cues, loops and recordings need room to be written, and that is exactly what the drive no longer has. The set can continue. What it cannot do is remember anything new.

On a recording in progress, their note is that when the memory runs out the recording stops automatically and the file is saved up to the moment just before the space ran out. So a set recorded onto a nearly full drive is not lost, it is cut short, at a point you did not choose.

So check the drive's free space before you press record, not after. A set recorded onto the last hundred megabytes of a drive ends when they do.

The space an exported library needs on the drive is published as a formula rather than a guess: AlphaTheta state that "A minimum of 600 kB is required to create a library. In addition, up to about 103 kB of free space is needed per track." They ask that you delete files from the drive beforehand to make room.

That is why this page and the export page are the same problem. A drive too full to save a cue point at the player is a drive too full to hold the database rekordbox writes at the next export, and that export fails at the end rather than at the start. Leave a gigabyte free on any drive you play from. It costs nothing and it removes both faults.

Free the space. Delete tracks you no longer play, or move to a bigger drive and export again from rekordbox rather than dragging files across. The size question has its own page, and the honest answer is that the drive should be big enough that this message never appears.

Then re-save the cues you lost. They were never written, so they are not on the drive to recover.

Keep playing. The message is not stopping the music and it will not.

Stop trying to save cues, and stop recording if you were. Neither will work until there is room, and there is no room to make in a booth. If you carry a second drive with the same export on it, which this site asks you to, switch to it for anything you need to save. Fix the full drive tomorrow.