Plex Remote Access Not Working after Software Update. Repair Plex in Program and Features
Disclaimer: Boring Video.
Plex Remote Access stopped working after a software update recently. This happened to me on 8/8/2018.
I tried a bunch of things on my router (even moving my computer to the DMZ) but the error: "not available outside your network" was always appearing.
1) Adjust router (enable upnp or move to DMZ (not recommended))
2) Disabled windows firewall. (this allowed access, but not optimal since I want the firewall on)
Finally I decided to go into control panel, default programs, and finally programs and features.
There you can find the Plex application and click on "Change"
Finally you can click "repair"
That's it.. this will hopefully fix permissions on the windows firewall side. NOTE I am using windows 10 basic.
You're problem might be a router network issue.