FYI…
PMS Version 1.17.0.1709
503 Service Unavailable
What I get when trying to access Plex…
That includes from the taskbar icon…
was able to exit Plex, but could not restart PMS…
rebooted
it’s back
Edit…
Found another server same symptoms.
WEB client Version 4.10.1 is the only change over time for any of the system