.mkv videos refuse to play whilst other formats work fine

[adastomek]

Server Version#:1.23.3.4707
FreeNas-11.3-U4.1 (Plex Media Server installed through plugin)
Processor: AMD FX-6300
RAM: 24GB
Video Card: Some old nvidia card I found.
Player Version#: Plex Web: 4.61.2; Windows client: 1.33.0.2444-a220eae4; IOS app: 7.21

Hi All,

Like the title says I noticed yesterday some of my TV shows and Movies weren’t playing, instead buffering without end, narrowed it down to the ones that were .mkv’s. (so mp4’s play flawlessley)

For the logs attached I have:

Restarted the server => Tried to play a movie => Waited a couple minutes

I’ve looked through a couple support threads here already and tried to troubleshoot myself, this is what i’ve done so far:

• Following this post I checked my pool sizes and can confirm that I have at least 500GB free space left.

• Following this post I looked through my pools and checked whether exec was “on”, they were

• Reinstalled the Plex media server, this presented a new symptom: a sustained ~100% cpu load (Freenas identified the process as Plex Transcode) despite not starting a video. (I “fixed” this by setting “Generate video preview thumbnails” ect. to never, however but it might still be linked to the original problem)

Whilst I can’t say for sure I feel that this issue only came up after updating to 1.23.5.4862 a few days ago (from a version a few months old) could just be a coincidence though, felt I should mention it incase it helps.

I have also recreated this issue on my Android TV and IOS app so it dosent look like a client issue to me (but what do I know)

Thanks for taking the time to read through my support request, and let me know if you need any additional info

Adam

(Edit: added Player Versions)

Plex Media Server Logs_2021-07-27_23-54-32.zip (1.4 MB)

[anon18523487]

The Web client doesn’t support mkv so it has to copy the streams over in a direct stream operation. Are you able to play anything that requires a transcode? I’m wondering if the permissions for your transcode folder are wrong so PMS can’t produce the output it needs.

[adastomek]

Hi,

Thanks for the reply I’ve tried a few videos but I cant get any transcoding to play (sometimes the dashboard says transcoding but the video continues to buffer like before), I’ve attached a log of a direct play that does work in case it helps.

I’ve also tried it on a windows client (ver: 1.33.0.2444-a220eae4) and it manages to play the videos there (but through direct play). If I switch off Direct Play however the problem comes up again for both transcoding and Direct Stream.

Do you know where the default location for the transcode folder is?

Again thanks for your reply

Plex Media Server Logs_2021-07-28_11-40-30.zip (797.4 KB)

[adastomek]

@anon18523487

I’m wondering if the permissions for your transcode folder are wrong so PMS can’t produce the output it needs.

In terms of permissions I dont think there’s anything wrong, i’ve run inside the jail:

ls -la

on the directories to “/Plex Media Server/Cache/Transcode” (where I think the Transcode folder is)

root (/) (note: incomplete):

drwxr-xr-x   2 plex  plex      2 Jul 28 11:08 Plex
drwxrwxr-x   9 plex  plex     10 Jul 28 17:38 Plex Media Server

/Plex Media Server:

drwxrwxr-x   9 plex  plex    10 Jul 28 17:38 .
drwxr-xr-x  20 root  wheel   25 Jul 28 17:45 ..
drwxrwxrwx   5 plex  plex    14 Jul 28 17:26 Cache
drwxrwxrwx   4 plex  plex     5 Jul 28 11:21 Codecs
drwxr-xr-x   3 plex  plex    30 Jul 28 17:27 Logs
drwxr-xr-x   3 plex  plex     3 Jul 28 11:12 Media
drwxr-xr-x   4 plex  plex     4 Jul 28 11:13 Metadata
drwxr-xr-x   7 plex  plex     7 Jul 28 11:09 Plug-in Support
drwxr-xr-x   2 plex  plex     2 Jul 28 11:08 Plug-ins
-rw-r--r--   1 plex  plex   911 Jul 28 17:38 Preferences.xml

/Plex Media Server/Cache:

drwxrwxrwx    5 plex  plex    14 Jul 28 17:26 .
drwxrwxr-x    9 plex  plex    10 Jul 28 17:38 ..
-rw-r--r--    1 plex  plex  3232 Jul 28 16:41 CloudAccessV2.dat
-rw-rw-r--    1 plex  plex  8976 Jul 28 11:38 CloudAccountV2.dat
-rw-r--r--    1 plex  plex    64 Jul 28 16:41 CloudUsersSubscriptionsV2.dat
-rw-r--r--    1 plex  plex    64 Jul 28 16:41 CloudUsersV2.dat
-rw-rw-r--    1 plex  plex  9472 Jul 28 11:38 Flags.dat
drwxrwxr-x    2 plex  plex     3 Jul 28 11:10 OCSP
drwxrwxr-x  256 plex  plex   256 Jul 28 17:19 PhotoTranscoder
-rw-rw-r--    1 plex  plex  7648 Jul 28 11:38 Privacy.dat
drwxrwxrwx    4 plex  plex     4 Jul 28 11:14 Transcode
-rw-rw-r--    1 plex  plex   352 Jul 28 11:38 UpdateChannels.dat
-rwxrwxr-x    1 plex  plex  9142 Jul 28 11:08 autotag_wordlist.json
-rwxrwxr-x    1 plex  plex  5753 Jul 28 11:10 cert-v2.p12

/Plex Media Server/Cache/Transcode:

drwxrwxrwx  4 plex  plex   4 Jul 28 11:14 .
drwxrwxrwx  5 plex  plex  14 Jul 28 17:26 ..
drwxrwxrwx  2 plex  plex   3 Jul 28 11:15 Detection
drwxrwxrwx  2 plex  plex   2 Jul 28 17:26 Sessions

As you can see i’ve tried increasing permissions for the relevant folders to see if that would do it, and making “plex” user the owner of several directories.

I’m not entirely sure where the default location is for the transcode folder (and I haven’t changed the transcoder temp directory either) so I could be looking in the wrong place.

[ChuckPa]

If I may augment here?

I looked at your logs.

1. I see no evidence of permission problems.
2. I do see where the server starts the transcoding request and sends several blocks to the transcoder. ( a PUT post)
3. After several blocks have been queued (normal), the player switches and asks for them (a GET request)
4. The player accepts 3 of them then, within 1/2 second, disconnects the session.

The transcoder logs show only about 60K bytes have been transcoded (Plex Media Server.1.log & corresponding Transcoder log)

Either:

1. That specific video has a problem
   -or, if all MPEG2 files in MKV container –
2. the MKV reader and MPEG2VIDEO decoder are damaged.

The easiest thing to test next is to have PMS download fresh codecs.

1. Stop Plex
2. Get to the Codecs directory
3. Delete everything you see there EXCEPT the .device_id file (the license)
4. Start PMS
5. Playback again. – Allow a few extra seconds for it to start while fresh codecs are downloaded.

[adastomek]

Hi,

Thanks for your reply I followed your instructions:

1. Stopped Plex

service plexmediaserver stop

2. Codecs Directory

3. Deleted files except .device_id

Deleted the top two files in the Codecs directory

Started PMS

service plexmediaserver start

I checked and the files were re-downloaded after I started playback, after several minutes the problem persisted.

@ChuckPa

1. That specific video has a problem
   -or, if all MPEG2 files in MKV container –

I’ve Included a log where I tried playing several different videos following a server restart.
Plex Media Server Logs_2021-07-29_12-38-17.zip (2.0 MB)

Another thing I noticed is that after some time trying to play a video I get an error code:
An unknown error occurred (4294967279)
Error code: 4294967279
Not sure if this helps.

Again thanks for taking the time to help me

(Edit: added error code)

[ChuckPa]

I don’t know if this will help but a similar problem was corrected in 1.23.6.

Is it easy to try 1.23.6 ?

[adastomek]

Hi,

Thanks for the pointer but I managed to fix it, (although i’m not too sure how).

So I noticed remote access wasn’t working (on account of me setting a new internal ip address when I reinstalled PMS when I first tried to fix the issue, and my router not liking it). I went to manually adding port forwarding and specifying the public port in Plex. For whatever reason my issue was fixed with my client devices now able to play transcoded video and convertion working.

Much appreciate the help I’ve gotten from @ChuckPa and @anon18523487, If I see this issue come up again I’ll try updating to 1.23.6.