Is it file system or application backup?
Could you write client name, alliases, hostname of client and output of this command from client side "printf "show name\nprint NSRLA\n"|nsradmin -p nsrexecd -i -" here (just replace names by something...)

Hi Moin,

honestly - if everything is fine, why do you ask the community at all?

So besides the general information like

  - operating systems

  - networker versions

  - networker module

  - etc (whatever is potentially helpful)

we need to know hat exactly you wanted to do at that momnet.

Is at least a manual backup (save) from the client working at all?

Hi,

Everything fine means basic configuration, firewall connection, backup software, client configuration.

Thanks for your suggestion.

Operating System : Windows 2k8 R2

Networker Version : 8.1.1.9

No module flat file system backup

8.1.x is end of primary support in 3 days - run away from it

Do you get this error with savefs or save?  Did you try client initiated backup (or savefs; depending on what it is)?