Can't access TMBackup (Time Machine) share - Authentication failed

[Darthajack]

A week ago the Shared Time Machine account (username TimeMachine and shared folder TMBackup) suddenly stopped working. No access. It's not just one Mac or an OSX version since 2 different computers with different versions (High Sierra and Catalina then Big Sur) stopped working. Trying everything to reconnect it, getting permission error. I made sure the password is correct on both ends, it's not that. I've even uninstalled HBS3, reinstalled, completely reset the NAS settings (resets users and shares but keeps data), reinstalling HBS3 again—nothing will do. Also completely deleted all Keychain account pointing to the TMbackup share, started over, won't work. I originally had QTS 4.4.x.xxxx when it started, I upgraded to QTS 4.5.1.1480 and that didn't help either. I even completely reset my wifi router just in case.

Trying to connect to TMBackup with Finder using go > connect to server > smb://TimeMachine@nasname/TMBackup I get a "you do not have permission to access this server" error. Time Machine can see the share, but trying to use that disk also gives me an authentication error. At some point I could see the TMBackup with an AFP connection and could even access the content. But not by SMB.

All other authenticated shares with another username work fine.

Seem really an issue with permission on TMBackup. Thing is in control panel, when you go to shares, there are no settings for that particular shared folder, it is different from others, so can't really play with it. And the Time Machine service user "TimeMachine" doesn't show up in users.

I sent a ticket to QNAP, no reply.

Do anyone have a solution? If not specific to this, do anyone know a way to completely reset the TimeMachine account or TMBackup permissions?

Thanks in advance.

[Darthajack]

QNAP never even replied to the ticket. I gave up waiting and found a workaround.

I just enabled the Time Machine with different user accounts, created a new user just for Time Machine backups, created a shared folder, made is a Time Machine folder in properties, moved the old backups in this new folder and set that shared folder as the Time Machine backup on each computer. Backups resumed where they had left off before TMBackup stopped working. Works fine now.

This doesn't explain or solve the issue, but at least my backups are back up and running.

QNAP service is appalling. Many people reported similar authentication issue, as well as many other issues to which QNAP just turns a blind eye. They don't care. I'm moving to another NAS solution as soon as it's convenient.

[wyattd]

Found exactly same issue. Resolved same way but still trying to find a solution to remove the TMBackup share which was originally created via HBS3. In the NAS Control panel - Shared Folders there is no access to its permissions not even via administrators. Just looks like its the way HBS3 initiated the protection on this folder.

I'm assuming this will need getting to its file attributes directly on the NAS via terminal, but as of yet I have not learnt enough about how the NAS file structure works to access this way.

I attach an image of how this looks on my NAS - Control Panel - Shared Folder view and wonder if you could confirm this is how you also see it.

If you've found any answers to this issue since your original post I would be interested.

Cheers
David