"Cannot load M3U8: 404 not found" for live TV when remote

I have been trying to figure this out for a while.  Everything works great with the Tablo app for Plex when I am on the same network  Recorded shows and live TV all work great.

The problem occurs when I am on the road and trying to watch live TV through the Tablo channel on Plex.  I generally take my Roku with me and using Plex is the only way to do it remotely.  Everything works just fine for recorded shows, they play just fine.  However trying to play live TV always results in an “Unable to play media file” error.

In an effort to debug the problem I tried to play live TV through the Plex applications for Android, iOS and OSX, as well as the web app. I tried to follow all of the suggestions and disable direct play and direct streaming.  In the web app, I also disabled the experimental player, which showed the Cannot load M3U8: 404 not found error.

Searching for that error led me to several threads on the Plex forums which all seem to point at a transcoding issue.  The common solution seemed to be to set a temp directory for transcoding, which I did, but that did not solve the issue.

With that directory set however I could monitor it and see whether Plex was writing to it, which it did for everything that could be played successfully: items in my Plex library,Tablo channel recorded shows, anything from any other channel I tested.  Whenever I tried live TV the transcode temp directory remained empty, and nothing would play.  

I’m not sure what else to do to try and get Live TV playing remotely through Plex.  Any help would be appreciated.  The Plex server is running the latest PlexPass version from a docker image on an unRaid Linux server if that makes any difference.

@skraut They made some changes to live tv in the last tablo firmware update they may have inadvertly affected Plex, They are aware of them and I believe are working on a fix for the next firmware version. 

I seem to have gotten around the cross domain issue by directly accessing my server (using either the IP, or a local hosts entry to resolve the hostname to the IP) rather than using the Plex.tv redirect - however, I’m still having issues with playing live TV remotely.

Basically, I get all the way to press Play at the channel page, and then nothing happens (constant spinning wheel). Looking in the Tablo plugin log it looks like everything is being sent off to tablo and then to Plex, and the Plex System log shows a connect out to the m3u8 stream, but then nothing happens. Putting that same stream URL into VLC results in a video stream being played…so something with Plex handling the stream and returning it is still a bit weird.

I can pull logs later if it helps anything.

@Davidvr @skraut    I seem to be experiencing a very similar problem but the message I receive is “Cannot load M3U8: Cross domain access denied”   Is this likely the same thing?

@JohnT  I think the Cross Domain error is resolved by making sure that direct play and direct streaming are disabled in your Plex client settings.

@skraut   Thank you!  That appears to have done the trick with a remote Chrome web client.