Synology hyper backup failed to run backup task

Needing help for Hyper backup tasks not working over the last 5 days. Am getting error of 'target offline' when checking/trying to run the hyper backup task from DSM.
errors in hyper backup log:

[Network][Synology NAS 1] Failed to start backup task. (The backup service is not available. Please re-enable the backup service at the destination.)

[Network][rsync DICOM to Home] Exception occurred while backing up data. (The backup service is not running. Please check the backup service settings or the firewall settings.)

Is this a simple fix? How do I 're-enable' the backup service at destination/what backup service settings do I need to check?

Apologies if a basic question but this is not my area of expertise. I have tried to do a basic search at Synology for a fix and in these forums but can't seem to find the answer.
Thanks
Brendan

Source NAS: Can connect to this from outside LAN/ QuickConnect is up and running on control panel. Source is DSJ216 at work
Destination NAS (at home): Can log into this ok. user there functions. Destination is 916+ at home.

It looks like your destination side is blocking access over 6281 HB port. Make sure you have your destination router configured to port forward that port to your nas and then try again.

UPDATE: Jinx @WST16 !

It could be Hyper Backup Vault. See if you have it on the target and start it/restart it.

Hyper Backup Vault - Add-on Packages | Synology Inc.

Hyper Backup Vault allows another Synology server to perform backup to this Synology NAS via Hyper Backup. Hyper Backup Vault also provides the overview of all the backup targets on this Synology NAS.

thanks.... just checked:
OK so Hyper Backup Vault has nothing listed under 'running tasks', and my previous backup task listed under the 'All Task' tab.

Sooo..... odes this mean no tasks are running?
How do I restart the Hyper Backup Fault?

If it's installed, it should be on the drop-down menu. We're talking about the target NAS here. If it’s not, then I’m not sure how your backups were running.

Edit: Are they both (source and target) on the same LAN?

Yes, I have it on the desktop and drop-down of the target NAS. Still can't workup how to restart it...

It should start and launch the Hyper Backup Vault interface when you click it. It’s not happening?
Are they both on the same LAN (your source and target)?

-- post merged: 17. May 2021 --

Almost nothing to configure on HBV. It’s enough for it to be installed on the target Synology NAS.

If it’s still not working, is it ok for you to restart this NAS (target)? Without knowing much about the configuration I'm hoping that a restart will reset something hanging and the service resumes (since you’re saying it was working before).

If you don’t want to restart the NAS, you can try stopping the service and running it again from Package Center > Installed and see if the backup runs.
Package Center should be on your menu too.

OK, so here are the details and what I've tried so far:
Source NAS: At work
Destination NAS; at home
Hyper backup's on source/work NAS not working.
Have tried restarting both the home and work NAS computers. Have also rebooted the work modem (all other computers/accesses at work working fine)

I can log into the work NAS fine remotely; also the external access is listed as 'normal' under the DDNS tab.
All the Hyper Backup tasks list 'target offline', even othugh target NAS is up and running well.

I am thinking it is port mapping access/restrictions on the modem not allowing the Hyper Backup service to run? We did recently have a new business modem installed several weeks ago. I have been trying to add the network ports listed by Synology that are used for backup (eg 22, 6281) but not luck so far with this helping

So the target is remote. It's highly possible that it's a ports thing. Make sure you’re forwarding the same port used by Hyper Backup task on the source.

Post a screenshot of the port forwarding page if you think it helps.

It looks like your destination side is blocking access over 6281 HB port. Make sure you have your destination router configured to port forward that port to your nas and then try again.

UPDATE: Jinx @WST16 !

It looks like your destination side is blocking access over 6281 HB port. Make sure you have your destination router configured to port forward that port to your nas and then try again.

UPDATE: Jinx @WST16 !

Thanks.. yes, checked that and the modem/router at work is set to allow the NAS IP address access to port 6281 for TCP.. see screenshot from modem port forwarding config.

Thanks.. yes, checked that and the modem/router at work is set to allow the NAS IP address access to port 6281 for TCP.. see screenshot from modem port forwarding config.View attachment 3659

And its still not working?

Do you have that HB task setup using your public domain name behind HTTPS? Is it maybe the problem that the certificate expired?

And its still not working?

Do you have that HB task setup using your public domain name behind HTTPS? Is it maybe the problem that the certificate expired?

Hmm.. how do I check that?

Hmm.. how do I check that?

On the source side, check the task status and open it (Edit), then move to the Target tab and see if the verify button exists there that needs to be pushed to make the remote connection a trusted one.

Ofc this is only in the case of using the FQDN and over https.

yes, checked that and the modem/router at work is set to allow the NAS IP address access to port 6281 for TCP.

I thought your target is at home!
You should be forwarding ports at the target side.

It looks like your destination side is blocking access over 6281 HB port. Make sure you have your destination router configured to port forward that port to your nas and then try again.

UPDATE: Jinx @WST16 !

DOH!!
YOU ARE CORRECT.. I had concentrated on the port forwarding on the source side and had not checked the DESTINATION NAS (home 916+).... I logged into the modem/router there and added 6281 port forwarding and bingo! All backing up now. We do have occ power failures at home and glitches so I suspect the modem/router had glitched. Just checked.. has completed backup of the 4 Hyper backup tasks..... so assuming will continue to do so baed on schedule. Thanks!!!