Any luck? I was having the same issue. Haven’t been able to access Live TV in awhile on my HD HomeRun Extend. Same “There was an unexpected error. Please visit our forums if you continue to experience problems” for me. I found this post though, and it helped me. Give it a try:
https://forums.plex.tv/t/workaround-there-was-an-unexpected-error-when-going-to-settings-page/765299/4
Everything seems to be working fine now. Except for some jerky playback… 
–Kyle
