I spent a day unable to get beyond the postcode screen to use the HD HomeRun with Plex. It was frustrating there was no phone number for Plex support, even though I had just signed up for paid membership. No way would it work with my valid UK postcode (first part). I finally found I could click on the XMLTV option and type: http://www.xmltv.co.uk/feed/6743 . Then I could continue and it loaded the EPG for UK Freeview using that online data feed. As I type it now appears to be downloading the EPG data successfully.
