This is a plex.tv website issue and the way it handles media library URL’s.
When not logged into the plex.tv website and a media https URL is clicked on from anywhere, etc. (which opens a browser), the plex.tv page comes up with an error “Not found. We can’t find the page you’re looking for”.
For users who are NOT logged in, the plex.tv page should redirect to the login page to allow users to login to their plex account, and once logged in then proceed as normal to the original requested link.
Example http URL:
https://app.plex.tv/desktop/#!/server//details?key=%2flibrary%2Fmetadata%
Not sure why this wasn’t already catered for, it’s how many other websites deal with URL access that require a login.
