Browser Extensions install error

Just refreshed Firefox browser, which among other things removes all extensions.

Attempting to reinstall from Norton 360, internet security, browser extensions, it launches the browser and gets "internal server error".

I have gone instead to the Firefox add-on extension and at least installed the main extension I remember "Norton safe Web"

I didn't originally, but have now installed the latest Norton 360 version 22.23.3.8, getting same results.  I didn't need to install them, but have tried for the other internet browsers I have installed, Chrome and Edge, and they get same message.

Is this a known problem?  Temporary server problem? other?