Bitdefender Thunderbird Add-on No Longer appears


With the latest upgrade of Thunderbird to "Supernova", the Bitdefender Add-on Toolbar has disappeared. It's no longer listed in the "view" drop-down menu, even though the add-on shows it's "enabled" in Thunderbird.

I'd like to get that toolbar back. Any idea of how this can be done?

I tried disabling the toolbar and then closing Thunderbird. But when I run Thunderbird again, the toolbar add-on seems to re-enable itself . . . and it still doesn't show up

--- Rich