Try backup of only that saveset and see what happens (client initiated).

I did a client initiated backup for that saveset as you suggested and it success, no error, so please what i have to do when doing automatic backup.

I did a client initiated backup for that saveset as you suggested and it success, no error, so please what i have to do when doing automatic backup.

OK, try now only that saveset, but as server initiated. If that works, try it with other savesets from that box and as last thing together with other clients in group.

Well, it could be few things. If you can, stop NW server and delete content of /nsr/tmp on server and try again after starting server. This is to see if some cached value is causing server side backups to fail. You can also enable verbosity on backup to see where it fails exactly. Make sure to test this with full and not incremental backup.

I tried to backup only that saveset as server initiated but still facing the same error.

I stop the services and deleted the content of tmp folder and restart the services, when i backed up the saveset i am still getting the same error.

Ask support to give you dbgcommand, raise debug on server side and try again to see where it breaks and why.