This issue is usually caused by incurrent  auth method or corrupt peer information.

1. Check auth method:

Run the following commands on both NetWorker Server and the problematic client:

C:\>nsradmin -p nsrexec
NetWorker administration program.
Use the "help" command for help.
nsradmin> . type: nsrla
Current query set
nsradmin> show auth methods
nsradmin> print

Does it show as below on both NetWorker Server and the problematic client?

auth methods: "0.0.0.0/0,nsrauth/oldauth"; 

If not, run:

update auth methods:"0.0.0.0/0, nsrauth/oldauth "

2. Update peer information:

On the client:

nsradmin -p nsrexec
print type: nsr peer information; name:
delete

On the networker server:

nsradmin -p nsrexec
print type: nsr peer information; name:
delete

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Best Regards,
Tim
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