Why does Serato say the library failed to open?

What the message means

Serato does not keep your library in one place. Each drive you add music from gets its own _Serato_ folder at its top level, holding the crates and library data for the tracks on that drive. Your Mac has one in ~/Music/_Serato_. On Serato DJ Pro 4 there is also the main library database, master.sqlite, in ~/Library/Application Support/Serato/Library. The full map is in what is in the _Serato_ folder.

“Failed to open” means Serato could not read or write one of those locations when it started. The message usually names the location, and that is your best clue.

Is it the drive or the library?

• The message names an external drive (a path starting /Volumes/). Start with the drive: connection, permissions, format and free space, steps 2 to 5. Tracks on your other drives usually still work, which is a strong sign the library itself is fine.
• It happens with no external drive connected, or the main library will not load. Think free space on the Mac, running two Serato versions, or a damaged database, steps 5 to 7.
• It started right after a Serato update. See the version section below, then crates missing after a Serato 4 or 5 update.

macOS permissions

Since macOS 10.15 Catalina, Serato needs your permission to read removable drives. macOS asks the first time you launch Serato with a drive connected. If you clicked Don’t Allow, or never saw the prompt, Serato cannot reach the drive. Serato’s support team says a missing permission can also stop imported tracks from staying in the library after a restart, which looks like the library failing to save. Turn on Removable Volumes under Files and Folders, and Full Disk Access if that alone does not fix it.

Read-only drives and NTFS

A drive formatted NTFS, the Windows format, can be read by a Mac but not written to without extra software. Serato also treats encrypted drives, drives with a write-protect switch and drives with restricted permissions as read-only. It marks a read-only drive with a gold lock in the Files panel, and any change you make to its crates, cues or analysis lasts only until you quit.

The fix is to reformat, which erases the drive, so copy everything off first. Use APFS or Mac OS Extended if the drive only ever plugs into a Mac, or exFAT if it also goes into a PC. More in how to run a Serato library from an external drive.

Low disk space

Serato writes to its library files while it runs, and on Serato 4 it also saves database backups and exports your crates when you quit. A drive with almost no space left can cause those writes to fail. Serato’s advice when a Serato 4 import fails is to free at least 5 GB on the drive your library lives on, so treat that as your minimum.

Two versions of Serato

You can keep more than one version of Serato DJ Pro installed, by renaming the old app in Applications before installing a new one. But Serato warns never to run two at the same time, because it can cause problems with the library database. Quit one completely before opening the other.

Opening a library in a newer version can also upgrade its database to a newer format. On Serato 4, Serato saves a copy first, as a zip named like master.sqlite-schema_v38-upgrade-<date>.zip in Library/Backups. If you go back to an older version and the library will not open, go forward to the newer version again rather than forcing the older one.

When it really is a damaged database

If the drive is healthy, writable, has space and only one Serato is running, the database may be damaged. It usually happens when Serato is force-quit or a drive is pulled while Serato is writing. Restoring it from Serato’s own backups takes a few minutes and keeps your crates, cues and beatgrids: follow how to fix a corrupt Serato database. Never delete a _Serato_ folder to start fresh. Rename it, so you can put it back.

If Serato crashes instead of showing a message, see why Serato keeps crashing or freezing.

After the library opens again

A library that failed to open often comes back with some tracks orange, because a drive was missing or a path changed along the way. Crate Cleaner scans your whole Serato library and lists missing, corrupt and duplicate tracks in one read-only pass, so you can see at once whether anything was lost. Library Repair then finds the missing files on disk and relinks them with their crates and cues. The scan is free on your real library, and the free plan relinks 5 tracks a day.

Try Crate Cleaner free →

FAQ

Did I lose my crates? Almost certainly not. Crates are saved as .crate files in the Subcrates folder of each _Serato_ folder, and Serato 4 also keeps database backups. Fix the cause and they come back.

Why does it only happen with one external drive? Each drive has its own _Serato_ folder. If that one drive is not allowed in macOS permissions, is formatted NTFS, is full or is failing, only its library fails to open.

Does Serato work with NTFS drives on a Mac? Only to read. macOS cannot write to NTFS without extra software, so Serato cannot save crates, cues or analysis there. Reformat to exFAT or APFS after copying your music off.

Can I delete the _Serato_ folder on the drive to reset it? No, it holds that drive’s crates. If you need Serato to start that drive fresh, rename the folder so you can put it back.

Why does the error keep coming back? Usually the drive: it is failing, it is on a hub, or it gets unplugged while Serato is open. Run First Aid, connect it directly, and always quit Serato before ejecting.