This is a recent problem as I have been a Plex user and Avast Internet Security subscriber for 2-3 years now. I have tried adding new rules to Avast or allowing certain ports, but the problem persists. Only when I disable the Avast firewall can I connect to the Plex Server. I am running Windows 7 and the latest version of the Plex Media Server. I have tried to install and re-isntall the Plex, but that changes nothing. Any help is welcomed. Perhaps this was discussed/resolved by somebody, but I could not find the thread.