When editing the Backup Configuration, if you click 'Save' without entering the passphrase, the following error is displayed, and the changes cannot be saved.
"No passphrase specified. Not allowed to reuse passphrase as no passphrase exists in system for fileserver URL {0}."
VMware NSX-T Data Center 3.0
VMware NSX-T Data Center 3.1
VMware NSX-T Data Center 3.2
VMware NSX 4.0
Inputting a passphrase is mandatory to save the backup configuration, but the issue is that the 'red asterisk' is not displayed in the passphrase field and the 'Save' button can be clicked even if the passphrase has not been entered.
This issue is resolved in VMware NSX 4.1.1
Workaround:
Follow the UI error message and input the passphrase to save the settings.