Backup stuck in infinate loop

Duplicati 2.0.6.3
Mono 6.8.0.105
Raspberry Pi 32Bit
Native install - Not Docker

This one is driving me nuts ! I’m fairly familiar with Duplicati and have run in on many different platforms.
This install is working but goes wrong at the end of the backup job.
As it finishes I get a “Disconnected from server” error - reconnecting in 15 seconds, which it does; then the job starts again. This takes about 4 minutes as there have been no real changes in the data set. Overnight this means I get in excess of 100 backups recorded in the logs - all of which report as successful.
Anyone got any ideas what might be going on ?

The only other oddity is sometimes after a reboot there is no backup job shown in Duplicati UI at all. After a while after a reload of the UI the job mysteriously appears as normal.

Any help greatly appreciated.

Welcome to the forum @Nicholas_Marlow

I’m not finding that exact message. Might it have looked like below?

image

If so, the JavaScript in the web browser (which is what) said that, and you can use its tools to look at this.
Most browsers have some sort of web developer tool available via F12 or a menu to look at network work.

Is Duplicati run as a systemd or other service, or run manually? Does ps show it stay steady or restart?

Do they show up in the Restore dropdown? That’s late in the backup itself, but other steps run even later.
Have you watched the status bar to see what it says before disconnect occurs? Do you send any email?
Mail sending failing after upgrade to Debian 11 might be relevant, but details are thin, both here and there.
Does the backup job run on a schedule? If a scheduled backup doesn’t run, it will run on Duplicati restart.
With GUI coming and going, you can do better with log-file=<path> log-file-log-level=information (at least).

Thanks for the reply, you are spot on. And sorry, I should have pasted the full message in the first place.
I am able to see those lines as you posted in the JavaScript by hitting F12. My IT skills are very much in hardware and OS so I don’t really know what I’m looking at. Are you saying there will be a clue as what is throwing the error somewhere in that Java ?

you did not answer about the install with or without systemd. If it’s as a service, can you post the output of

systemctl cat duplicati

You’re right ! In fact I did not answer quite a few of your points. Bear with me and I’ll be back.

Car stolen this week so I’m a bit distracted I think !