Cannot Add new library or edit existing one

Done. No change. Sticks at the select type window with no selection available in the Language choice.

Another possible clue: when I attempt to access the web interface at “[http://]localhost:32400/web/” with a resulting error message “404 Not Found”. Tried the IP address of the server too. No change.

I can see everything including the settings using “[https://]app.plex[.]tv/desktop/

Can’t be a browser issue as I’ve tried it on Edge, Chrome and Firefox. And Tautulli works fine using localhost.

Steps I’ve tried: Disabled all firewall and protection, VPN and antivirus (temporarily, of course) to see if something is being blocked. Been working on this for days and I’m ready to switch to a different media server. It’s getting very frustrating.

Any other suggestions are appreciated.

Thanks!
BW