Everything was good before the clean install of OS Sierra, but now the Plex app on the ATV won't see the content on my external hard drive. PMS does see the music I have installed on my iMac, and the files on my WD My Book Live are showing up and are working on my iMac.
I've made no other changes.
When I click on the Apple TV menu item in the upper right hand corner, I get, "There was a problem connecting to this player."
In settings, I have:
Not available outside your network
Your server is signed in to Plex, but is not reachable from outside your network. Learn more
Farther down that page it shows a Private IP address with a green arrow, next to it is a Public IP address with a red X.
Port is not set to manual and is at 32400.
I've don't have a firewall set up. No proxies. I checked the external settings. I've logged out and logged back in. All the device names match.