The steps to resolve the issue of the client "ClientAB" not being in the backup server's clients list are as follows:

Verify the client name:

On the NetWorker server, open the NetWorker Management Console.

Go to the Clients tab.

Verify that the client "ClientA" is present in the list of clients.

Verify that the client "ClientAB" is not present in the list of clients.

Update the client name:

On the NetWorker server, open the NetWorker Management Console.

Go to the Clients tab.

Click on the ClientA.

In the Client Name field, update the name to "ClientAB"

In the Client Address field, enter the IP address or hostname of the client.

Click on the OK button to save the changes.

Re-schedule the backup

Go to the Clients tab.

Click on the ClientAB.

Go to the Schedules tab.

Remove the current schedule and create a new schedule for the client.

Select the appropriate schedule for the backup.

In the Save Set field, select the save set that you need to backup.

Click on the OK button to schedule the backup.

Monitor the backup process

Monitor the backup process to ensure that it is running successfully.

Check the logs for any errors.