I just logged in to tell people to look into this quick and easy fix. My system was working fine for years too with no issues.
I am in the UK and use a Virgin Media Hub 3.0. I think that it must have updated itself at some point as all of my port forwarding rules were gone. However, this was the last check made, after messing around with Plex, uninstalling and reinstalling, losing shares and having to rebuild libraries.
The router fix took a few minutes, it is slow and clunky, had to use Chrome over Firefox too but as soon as I fixed ports I was back in business.
Hope this helps someone.
