SYMPTOMS:
When you are trying to change or delete client attributes from client list in master server properties, you get an error:
Unable to save data on some hosts
An error occurred on host example.com. The error is " (1)".
RESOLUTION:
1. Go to NetBackup installation folder (usually it's %PROGRAMFILES%\Veritas\NetBackup). Then proceed to db\client\<client.name> folder.
2. If there is only one file and it is named "GP_", go to step 3. If not, I can't guarantee anything.
3. Delete db\client\<client.name> folder.
4. Restart NBU services.