Can you post a screenshot showing the precise error message? That might progress diagnosis a bit further. Thanks.
That’s all I have to go on. I have to reboot the core each time there is a failed backup in order to get past the error message screen.
Hi @Vaughan_Barnacle,
I’ve activated diagnostics on your account and I found the logs from one of your backup failures.
11/25 14:04:02 Warn: [Broker:Misc] [broker] validation failed: System.InvalidOperationException: invalid datatype: 227
at System.Sooid._ValidateDataType(_DataType datatype)
at System.Sooid..ctor(Byte type, _DataType datatype, Byte[] b, Int32 off, Int32 count)
at Sooloos.Broker.TinySooidDb.Vacuum(VacuumOperation op, KeySpace ks_from, KeySpace ks_to)
at Sooloos.Broker.VacuumOperation.Run()
at Sooloos.Broker.Database.Validate()
11/25 14:04:02 Error: [Broker:Misc] [broker/database] corruption detected: invalid datatype: 227
11/25 14:04:02 Warn: [Broker:Misc] [broker] detected corrupt database, notifying client
11/25 14:04:02 Warn: [Broker:Misc] [broker] detected corrupt database, halting broker threads
Roon thinks your database is corrupted. That is what is preventing the backup from completing. To prove for sure whether that’s the case you can try to backup with a clean, new database. Please try that and let us know whether it works.
So at the start of all this (see beginning of this thread) I installed a new SSD in the core, reinstalled all my music. Still the same problem. Restoring from a recent backup worked fine, but of course, the error in backing up persists.
Is it possible to drill down into exactly what is making it fall over?
Hi Vaughn,
Fellow user here but willing to help since support is off til Monday.
Daniel showed you the log where it says specifically your database is corrupted and thus won’t back up.
It could be because your backup is corrupted somehow. He asked you to create a new database without restoring and try backing that up. Did you do that and if so was it the same result?
Hi Daniel
Yes, I have now got about 5 or 6 different server folders on my Roon Rock. Tried the new database option several times. I don’t think I have tried a backup before restoring, but I’m loathed to try that now as my latest backup is about two or three weeks old (a lot of changes since then). On the basis that Roon supposedly can’t backup a corrupt database, then a completely new library installation (which I’ve done), then a restore from a working backup should be ok. But then it refuses to perform a backup. Weird thing is: there were no changes to my library after my last successful backup and the next failed one. The restoration of the working backup should give a database that can be restored, but it doesn’t.
Hey @Vaughan_Barnacle,
Thanks for the follow-ups!
Unfortunately with corruption, your options are to create a completely fresh database, or find an older backup that predates the issues you’re having in hopes that it also predates the cause of corruption.
Unfortunately, we’re only given the diagnostic information we’ve shared with you above, which doesn’t point to a specific file. If you’re able to, it won’t hurt to scan your local library for any corrupted or issue files.
Are you still failing to create a fresh backup? We’re still only seeing the diagnostic report from ~11/25 in which the backup fails due to the same issue causing the database to become corrupted.
It’s disappointing not to be able to pinpoint the issue. I will try scanning my flac files, but the issue has persisted since reloading all the music onto a new SSD. I only have two backups. Restoring either of them doesn’t solve the problem. Ironic that Roon found no issues with the database when it backed it up, but then says it’s corrupt when you restore it. And, isn’t Roon supposed to no longer be able to backup a corrupted database? All very odd. I am not trying further backups at the moment, because it means I have to keep rebooting the Roon core. That game got really old, really quickly. I’m about ready to give up on finding a solution to this - life’s too short. I will try checking the FLACs, then I’m done.
So I have tested all my FLAC files. Zero errors.
Hey @Vaughan_Barnacle,
The best next step here would be to set up a fresh database and re-import your local library.
It may be worth increasing the auto backup schedule - many users also find it useful to set up multiple backup locations.
Let us know if you continue to run into issues after setting up a fresh database - you have my apologies in that this is a less-than-ideal situation and process. 
So, you’re saying I have to lose all the data stored on my backup? Back to square 1? When there’s nothing wrong with any of my music files and I am using brand new discs? If so, then Roon needs to work on a new script that will identify what it thinks is corrupt, rather than just throwing it’s hands up in the air and leaving us all guessing.