"There was a transcoder error" failed recordings on Plex DVR

My recordings have been failing with increasing regularity on Plex DVR. This is true of the current release (1.10.1.4561), and the previous 3 or four releases at least. In Recording schedule, I get a yellow exclamation mark and a message of “There was a transcoder error”. As far as I know, there is no transcoding set for recordings.
This has happened on a variety of recordings, although some seem more susceptible than others. There’s no clear pattern, however.
I have just done a clean re-install (uninstalled as per instructions on the Plex site) and the problem is still occurring.
When it occurs, the following appears in the logs (sanitised):

Dec 08, 2017 23:10:51.653 [0x7f478bffe700] DEBUG - Auth: authenticated user 1 as xxx@xxx
Dec 08, 2017 23:10:51.653 [0x7f477afff700] DEBUG - Request: [IPAddress:33682 (Subnet)] GET /player/proxy/poll?deviceClass=pc&protocolVersion=1&protocolCapabilities=timeline%2Cplayback%2Cnavigation%2Cmirror%2Cplayqueues&timeout=1 (10 live) GZIP Signed-in Token (roger@rnpickard.me.uk)
Dec 08, 2017 23:10:51.653 [0x7f477afff700] DEBUG - Beginning read from two-way stream.
Dec 08, 2017 23:10:52.478 [0x7f47617fa700] DEBUG - buildLiveM3U8: min 0 max 529
Dec 08, 2017 23:10:52.755 [0x7f475efff700] DEBUG - Using default transcode duration of 120 minutes
Dec 08, 2017 23:10:52.756 [0x7f475efff700] DEBUG - Started session successfully: 15f57183-c24e-423c-a2e8-c0e1b422e797
Dec 08, 2017 23:10:52.756 [0x7f475efff700] DEBUG - DVR:Recorder: It took 30.0 sec to start the session for http://127.0.0.1:32600/devices/compound_device072dvb%23v4l%23%2Fsys%2Fdevices%2Fpci0000%3A00%2F0000%3A00%3A14.0%2Fusb3%2F3-7%2F3-7%3A1.0%3A0013942974/media/triplet%3A%2F%2F9018%3A8197%3A8448?param=<%3Fxml%20version%3D"1.0"%20encoding%3D"UTF-8"%3F> <tunedata><tt>4<%2Ftt><dq>0<%2Fdq><dr%2F><fr>513800<%2Ffr><md>0<%2Fmd><sr>0<%2Fsr><pl>0<%2Fpl><lf>8<%2Flf><l1>0<%2Fl1><l2>0<%2Fl2><ls>0<%2Fls><pp>0<%2Fpp><hz>0<%2Fhz><in>0<%2Fin><fc>0<%2Ffc><t>8197<%2Ft><n>9018<%2Fn><s>8448<%2Fs><en>0<%2Fen><%2Ftunedata>
Dec 08, 2017 23:10:52.756 [0x7f475efff700] ERROR - DVR:Recorder: No part because session isn’t reporting one.
Dec 08, 2017 23:10:52.756 [0x7f475efff700] ERROR - DVR:Recorder: Couldn’t obtain a part, something went wrong.
Dec 08, 2017 23:10:52.756 [0x7f475efff700] ERROR - DVR:Recorder: Error 12 (There was a transcoder error) starting the record, shutting things down.
Dec 08, 2017 23:10:52.756 [0x7f475efff700] DEBUG - DVR:Recorder: Asked to stop recording ‘Program name’.
Dec 08, 2017 23:10:52.756 [0x7f475efff700] DEBUG - DVR:Recorder: Stopping transcode session.
Dec 08, 2017 23:10:52.756 [0x7f475efff700] DEBUG - Killing job.
Dec 08, 2017 23:10:52.756 [0x7f475efff700] DEBUG - Signalling job ID 29728 with 9
Dec 08, 2017 23:10:52.756 [0x7f475efff700] DEBUG - Job was already killed, not killing again.
Dec 08, 2017 23:10:52.756 [0x7f475efff700] DEBUG - Stopping transcode session 15f57183-c24e-423c-a2e8-c0e1b422e797
Dec 08, 2017 23:10:52.756 [0x7f475efff700] DEBUG - Cleaning directory for session 15f57183-c24e-423c-a2e8-c0e1b422e797 (/var/lib/plexmediaserver/Library/Application Support/Plex Media Server/Cache/Transcode/Sessions/plex-transcode-15f57183-c24e-423c-a2e8-c0e1b422e797)
Dec 08, 2017 23:10:52.756 [0x7f478e7ff700] DEBUG - JobManager: child process killed by signal: 9 (Killed)
Dec 08, 2017 23:10:52.756 [0x7f478e7ff700] DEBUG - Jobs: ‘/usr/lib/plexmediaserver/Plex Transcoder’ exit code for process 29728 is -9
Dec 08, 2017 23:10:52.756 [0x7f475efff700] DEBUG - DVR:Grabber: Freed a tuner (now 1 available)
Dec 08, 2017 23:10:52.756 [0x7f475efff700] DEBUG - DVR:Grabber: Operation for Program name completed with status error (There was a transcoder error)
Dec 08, 2017 23:10:52.756 [0x7f475efff700] DEBUG - Activity: Ended activity 6d55c24f-d806-4cc9-9743-fa5a3e1c15b4.
Dec 08, 2017 23:10:52.757 [0x7f475efff700] ERROR - DVR:Grabber: Starting media grab failed.

This is pretty frustrating, as I would love to make Plex my main DVR, but I’m getting about a 75% failure rate on recordings, which makes it near useless.

Just wanted to chime in with a potential solution. I started experiencing this issue yesterday and it was driving me nuts. It seemed to come from nowhere, and nothing I tried would resolve it. I scoured the internet for advice and never found a solution, but I did notice several of the threads mentioned a mounted disk for the Plex library. My ubuntu server mounts a Synology NAS via NFS for library storage. I took a look at my NFS settings and made some changes that seem to have fixed this issue for me.

Initially I had this line in /etc/fstab

x.x.x.x:/volume1/media /mnt/nfs/media nfs rw,soft,intr,user,rsize=4194304,wsize=4194304,timeo=14,vers=4

I had set that up with “rsize” and “wsize” based on a recommendation I read on some forum somewhere, which supposedly made the NFS faster.

I decided to remove the “rsize”, “wsize” and “timeo”. I also realized I was missing the “0 0” that is supposed to be at the end. So now, my /etc/fstab entry looks like:

x.x.x.x:/volume1/Media /mnt/nfs/media nfs rw,soft,intr,user,vers=4 0 0

I rebooted, and now recordings work! I had rebooted half a dozen times beforehand and recordings hadn’t fixed themselves, so while possible that the reboot randomly fixed it, I think it has to be related to the nfs settings. I’ve also noticed a few less issues as well, my Nvidia Shield would randomly stop playback of non-tv content, which no longer seems to happen.

Anyway, I don’t fully understand the NFS settings to know how that may have helped, but something to try!

My recordings are going on to a local drive, albeit not the system drive. It’s mounted as “ext4 defaults 0 2”. I had some nfs drives mounted with permissions “user,intr,group,soft 0 0”, which I’ve now unmounted as Plex wasn’t using them,
I’m running Ubuntu server, if it helps anyone:

Dec 09, 2017 22:58:42.066 [0x7ff4cd3fe700] INFO - Plex Media Server v1.10.1.4561-9de2951fc - ubuntu PC x86_64 - build: linux-ubuntu-x86_64 ubuntu - GMT 00:00
Dec 09, 2017 22:58:42.066 [0x7ff4cd3fe700] INFO - Linux version: 4.4.0-92201708161632-generic (#0+mediatree+hauppauge-Ubuntu SMP Thu Aug 17 00:28:00 UTC 2017), language: en-GB
Dec 09, 2017 22:58:42.066 [0x7ff4cd3fe700] INFO - Processor Intel(R) Core™ i7-4770 CPU @ 3.40GHz
Dec 09, 2017 22:58:42.066 [0x7ff4cd3fe700] INFO - /usr/lib/plexmediaserver/Plex Media Server
It’s beginning to look like this is related to this:
https://forums.plex.tv/discussion/278307/dvr-transcoding-stalls-at-100-recorded/p3
and this:
https://forums.plex.tv/discussion/283156/status-of-100-complete-recording-bug/p20
both of which are allegedly being worked on, but have been major bugs for several releases now.

For anyone else having similar issues, I now seem to have a stable setup, but I had to switch OS to Windows. There seemed to be two issues manifesting in the same way:

  1. Hauppauge, despite their claims, do not appear to properly support Linux. Specifically, the second tuner appears not to work. There are a few reports out there about this. Specifically, I was seeing kernel panics when trying to tune a second channel. I tried this in Ubuntu 16.04 and 17.04, both stated as supported by Hauppauge, and 17.10 (latest release).
  2. A long USB extension cable to get the tuner close to the aerial socket and a (possibly) dodgy front panel USB socket. Changing to a very short cable (supplied with the tuner) and a rear panel socket improved reliatbility. This was seen (again) when attempting to use 2 tuners simultaneously, and was seen with WinTV as well, so definitely not Plex!

I have a qualifier that I only tried the short cable with older versions of Plex under Ubuntu 16.04 where the issue came up originally, and only on the front socket. It is possible that the OS has less impact than it appears, but the second tuner failed consistently on Linux and only intermittently and predominantly with 2 HD channels on Windows. If I have a burst of enthusiasm, I may try Ubuntu again, as I’d prefer not to have the nuisance and overhead of running Windows, but for now I have a stable system.

Conclusion: If you have this issue, check your USB connection and cables. Failing that (and I hate saying it!) switch to Windows where the driver works properly. Possibly better yet, switch to a better supported tuner!