Official comment
Hey Emi,
Sorry about that - it's likely that the drive you were using was removed from the player or computer before ejecting it and as such the database was corrupted. Please format the drive and try again, but if you see this error regularly, I would recommend trying a higher quality USB drive.
As for the DJM-REC app, please ensure that your DJM has the latest firmware installed and that you have given the app permission to use what it needs in the iOS security settings.
