# Can't Play Some MKV Files
**URL:** https://forums.plex.tv/t/cant-play-some-mkv-files/935768
**Category:** Plex Media Server
**Tags:** server-windows, playback
**Created:** [January 26, 2026, 3:43am UTC](https://forums.plex.tv/t/cant-play-some-mkv-files/935768 "2026-01-26T03:43:33Z")
**Posts on this page:** 15
**Page:** 1
### Author:  [@fuzbuster83](https://forums.plex.tv/u/fuzbuster83)
#### Post date: [January 26, 2026, 3:43am UTC](https://forums.plex.tv/t/cant-play-some-mkv-files/935768/1 "2026-01-26T03:43:33Z")
Server Version#: Version 1.42.2.10156
Player Version#: Version 4.147.1
I have a few home movies that I had converted professionally from an old camcorder to .MKV files. Some of them play in Plex, whether its on my phone, the smart TV, or the web, and other don’t. The ones that do not get an h4 (not supported) error. All the files play in VLC just fine. I checked the Details tab on the files’ Properties and they seem to be the exact same in the Audio and Video sections.
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### Author:  [@OttoKerner](https://forums.plex.tv/u/OttoKerner)
#### Post date: [January 26, 2026, 11:55am UTC](https://forums.plex.tv/t/cant-play-some-mkv-files/935768/2 "2026-01-26T11:55:44Z")
Please post a mediainfo of one video that plays, as well from one video that doesn’t.
[download mediainfo here](https://mediaarea.net/en/MediaInfo "download mediainfo here")
File - Export - Text (Advanced mode)
Do also post some info about your Plex server. Particularly which GPU and CPU are in it, because that determines whether it can perform video transcoding (and whether it can use hardware support for that to reduce load).
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### Author:  [@fuzbuster83](https://forums.plex.tv/u/fuzbuster83)
#### Post date: [January 26, 2026, 1:58pm UTC](https://forums.plex.tv/t/cant-play-some-mkv-files/935768/3 "2026-01-26T13:58:35Z")
Below is the MediaInfo output:
General
Unique ID : 40682254410127613653686279771914038689 (0x1E9B1E00A57F78951A1BC7DF03ACEDA1)
Complete name : Z:\Jess Camcorder\Jessica1.mkv
Format : Matroska
Format version : Version 2
File size : 1.05 GiB
Duration : 31 min 33 s
Overall bit rate mode : Variable
Overall bit rate : 4 752 kb/s
Frame rate : 29.970 FPS
Encoded date : 2023-11-06 23:53:41 UTC
Writing application : MakeMKV 1.17.5 win(x64-release)
Writing library : libmakemkv 1.17.5 (1.3.10/1.5.2) win(x64-release)
Video
ID : 1
ID in the original source medium : 224 (0xE0)
Format : MPEG Video
Format version : Version 2
Format profile : Main@Main
Format settings : CustomMatrix / BVOP
Format settings, BVOP : Yes
Format settings, Matrix : Custom
Format settings, GOP : M=3, N=15
Format settings, picture structure : Frame
Codec ID : V\_MPEG2
Codec ID/Info : MPEG 1 or 2 Video
Duration : 31 min 33 s
Bit rate mode : Variable
Bit rate : 4 495 kb/s
Width : 720 pixels
Height : 480 pixels
Display aspect ratio : 4:3
Frame rate mode : Constant
Frame rate : 29.970 (29970/1000) FPS
Original frame rate : 29.970 (30000/1001) FPS
Standard : NTSC
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Top Field First
Compression mode : Lossy
Bits/(Pixel\*Frame) : 0.434
Time code of first frame : 00:00:00:00
Time code source : Group of pictures header
GOP, Open/Closed : Closed
Stream size : 1 014 MiB (94%)
Language : English
Default : No
Forced : No
Color primaries : BT.601 NTSC
Transfer characteristics : BT.601
Matrix coefficients : BT.470 System B/G
Original source medium : DVD-Video
Audio
ID : 2
ID in the original source medium : 189 (0xBD)128 (0x80)
Format : AC-3
Format/Info : Audio Coding 3
Commercial name : Dolby Digital
Codec ID : A\_AC3
Duration : 31 min 33 s
Bit rate mode : Constant
Bit rate : 256 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 31.250 FPS (1536 SPF)
Compression mode : Lossy
Stream size : 57.8 MiB (5%)
Title : Stereo
Language : English
Service kind : Complete Main
Default : Yes
Forced : No
Original source medium : DVD-Video
Dialog Normalization : -31 dB
compr : -11.02 dB
dialnorm\_Average : -31 dB
dialnorm\_Minimum : -31 dB
dialnorm\_Maximum : -31 dB
Menu
00:00:00.000 : en:Chapter 01
00:05:00.800 : en:Chapter 02
00:10:01.100 : en:Chapter 03
00:15:01.400 : en:Chapter 04
00:20:01.700 : en:Chapter 05
00:25:02.017 : en:Chapter 06
00:30:02.333 : en:Chapter 07
The machine running my Plex server is the following:
CPU: Intel N100 800MHz
RAM: 18GB
GPU: Intel UHD Graphics
It was purchased her based on the Plex forums feedback I was given:
> **[Amazon.com: Beelink Mini S12 Mini PC, 12th Intel Alder Lake- N95 (4C/4T, up to...](https://www.amazon.com/Beelink-Computer-Support-Display-Ethernet/dp/B0BVFVRDXN)**
>
> Amazon.com: Beelink Mini S12 Mini PC, 12th Intel Alder Lake- N95 (4C/4T, up to 3.4GHz), 8GB DDR4 256GB M.2 SSD, Mini Desktop Computer Support 4K@60Hz Dual Display/WiFi 6/BT5.2/USB 3.2/2.5GB LAN for Home/Office : Electronics
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### Author:  [@OttoKerner](https://forums.plex.tv/u/OttoKerner)
#### Post date: [January 26, 2026, 2:14pm UTC](https://forums.plex.tv/t/cant-play-some-mkv-files/935768/4 "2026-01-26T14:14:22Z")
Is the mediainfo from the file that _doesn’t_ play, or from the one that _does_ play?
I hoped that seeing both would be enlightening.
Which operating system is used on this computer? Windows or Linux?
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### Author:  [@fuzbuster83](https://forums.plex.tv/u/fuzbuster83)
#### Post date: [January 26, 2026, 3:00pm UTC](https://forums.plex.tv/t/cant-play-some-mkv-files/935768/5 "2026-01-26T15:00:19Z")
Oh, that is from one that does not play that was given to me by the media conversion company. Here is one from a video that plays without issue:
General
Complete name : Z:\Plex\Movies\Bang Bang (2024).mp4
Format : MPEG-4
Format profile : Base Media
Codec ID : isom (isom/iso2/avc1/mp41)
File size : 1.92 GiB
Duration : 1 h 43 min
Overall bit rate : 2 638 kb/s
Frame rate : 23.976 FPS
Writing application : Lavf60.4.101
Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Format settings : CABAC / 4 Ref Frames
Format settings, CABAC : Yes
Format settings, Reference frames : 4 frames
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 1 h 43 min
Bit rate : 2 250 kb/s
Maximum bit rate : 31.2 Mb/s
Width : 1 920 pixels
Height : 958 pixels
Display aspect ratio : 2.004
Frame rate mode : Constant
Frame rate : 23.976 (24000/1001) FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel\*Frame) : 0.051
Stream size : 1.63 GiB (85%)
Writing library : x264 core 164
Encoding settings : cabac=1 / ref=4 / deblock=1:-1:-1 / analyse=0x3:0x133 / me=umh / subme=9 / psy=1 / psy\_rd=1.00:0.15 / mixed\_ref=1 / me\_range=24 / chroma\_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast\_pskip=0 / chroma\_qp\_offset=-3 / threads=18 / lookahead\_threads=1 / sliced\_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray\_compat=0 / constrained\_intra=0 / bframes=3 / b\_pyramid=2 / b\_adapt=2 / b\_bias=0 / direct=3 / weightb=1 / open\_gop=0 / weightp=2 / keyint=250 / keyint\_min=23 / scenecut=40 / intra\_refresh=0 / rc\_lookahead=60 / rc=2pass / mbtree=1 / bitrate=2250 / ratetol=1.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / vbv\_maxrate=31250 / vbv\_bufsize=31250 / nal\_hrd=none / filler=0 / ip\_ratio=1.40 / aq=1:1.00
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709
Codec configuration box : avcC
Audio
ID : 2
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 1 h 43 min
Source duration : 1 h 43 min
Source\_Duration\_LastFrame : -11 ms
Bit rate mode : Constant
Bit rate : 384 kb/s
Channel(s) : 6 channels
Channel layout : C L R Ls Rs LFE
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 286 MiB (15%)
Source stream size : 286 MiB (15%)
Default : Yes
Alternate group : 1
The Plex server is running Windows 11 Pro 24H2.
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### Author:  [@OttoKerner](https://forums.plex.tv/u/OttoKerner)
#### Post date: [January 26, 2026, 3:51pm UTC](https://forums.plex.tv/t/cant-play-some-mkv-files/935768/6 "2026-01-26T15:51:52Z")
So, the two files are fundamentally different.
The non-playing is using the ancient MPEG2 video codec, that we had on DVDs.
And to make matters worse, it is interlaced video (for those old CRT screens).
The playing file on the other hand is using the one slightly more modern AVC/H.264 video codec and no interlaced video. This is more compatible with modern display technologies.
Still, it should normally be no problem to play an old MPEG2 video.
Now, we need to turn our attention to the used Plex client and the device where it’s installed.
Did you try Plex clients on different kinds of devices?
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### Author:  [@fuzbuster83](https://forums.plex.tv/u/fuzbuster83)
#### Post date: [January 26, 2026, 4:48pm UTC](https://forums.plex.tv/t/cant-play-some-mkv-files/935768/7 "2026-01-26T16:48:51Z")
I have tried on my PC in Chrome, a smartphone, and on a Roku stick running the Plex app. I was going to confirm with the Plex for Windows app, which I use daily, but when I opened it up to try there was an update and now it won’t open. I will work on that as a different issue.
Should I attempt to convert these videos?
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### Author:  [@fuzbuster83](https://forums.plex.tv/u/fuzbuster83)
#### Post date: [January 26, 2026, 5:31pm UTC](https://forums.plex.tv/t/cant-play-some-mkv-files/935768/8 "2026-01-26T17:31:49Z")
I got the Plex for Windows app working and I tried 3 random video and they all worked.
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### Author:  [@OttoKerner](https://forums.plex.tv/u/OttoKerner)
#### Post date: [January 26, 2026, 5:46pm UTC](https://forums.plex.tv/t/cant-play-some-mkv-files/935768/9 "2026-01-26T17:46:13Z")
> [@fuzbuster83](#):
>
> I tried 3 random video and they all worked.
Since the Desktop app pretty much never requires the server to transcode anything, I think it is safe to say that the issue is with the transcoder.
Did you install the graphics adapter driver software on the server machine?
What are your current settings on Settings - [server name] - ‘Show Advanced’ - Transcoder
?
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### Author:  [@fuzbuster83](https://forums.plex.tv/u/fuzbuster83)
#### Post date: [January 26, 2026, 6:02pm UTC](https://forums.plex.tv/t/cant-play-some-mkv-files/935768/10 "2026-01-26T18:02:51Z")
I have not updated the GPU driver. I have been running with the preloaded drivers from Beelink’s image that comes on this machine. I have downloaded the Intel Driver & Support Assistant and I’m running that now to look for driver updates on thie box.
The Transcoder settings on the server are:
Transcoder quality: Automatic
Transcoder temporary directory: Blank
Downloads temporary directory: Blank
Transcoder default throttle buffer: 60
Background transcoding x264 preset: Very fast
Enable HDR tone mapping: Checked
Tone Mapping Saturation: 1.1000000000000001
Tone Mapping Contrast: 1.2
Tone Mapping Brightness: 10
Disable video stream transcoding: Unchecked
Use hardware acceleration when available: Checked
Enable HEVC video Encoding (experimental): Never
Hardware transcoding device: Auto
Maximum simultaneous GPU transcodes: Unlimited
Maximum simultaneous CPU transcodes: Unlimited
Maximum simultaneous background video transcode: 1
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### Author:  [@fuzbuster83](https://forums.plex.tv/u/fuzbuster83)
#### Post date: [January 26, 2026, 6:04pm UTC](https://forums.plex.tv/t/cant-play-some-mkv-files/935768/11 "2026-01-26T18:04:11Z")
Also, the Intel tool is installing the update for Intel® Graphics Driver 32.0.101.7084 for 11th-14th Gen Intel® Core™ Processor Graphics, as well as a bluetooth and wi-fi driver update.
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### Author:  [@fuzbuster83](https://forums.plex.tv/u/fuzbuster83)
#### Post date: [January 26, 2026, 6:24pm UTC](https://forums.plex.tv/t/cant-play-some-mkv-files/935768/12 "2026-01-26T18:24:45Z")
All available Windows and Intel driver updates have been done. The issue has not resolved with those steps completed.
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### Author:  [@OttoKerner](https://forums.plex.tv/u/OttoKerner)
#### Post date: [January 26, 2026, 9:16pm UTC](https://forums.plex.tv/t/cant-play-some-mkv-files/935768/13 "2026-01-26T21:16:41Z")
Then I’m out of ideas, except converting those affected videos to a more modern codec, like AVC, or maybe even HEVC.
(Though keep the unmodified version you got from the digitizing service stored in a safe place. Just in case you later get access to a better deinterlacing/upscaling software, like e.g. [https://www.topazlabs.com/](https://www.topazlabs.com/) )
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### Author:  [@fuzbuster83](https://forums.plex.tv/u/fuzbuster83)
#### Post date: [January 26, 2026, 10:41pm UTC](https://forums.plex.tv/t/cant-play-some-mkv-files/935768/14 "2026-01-26T22:41:41Z")
Ok, thanks for trying! At least now I know why the Plex for Windows app works so much better than my browser. I will try to convert and see where I can get..
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### Author:  [@system](https://forums.plex.tv/u/system)
#### Post date: [April 26, 2026, 10:41pm UTC](https://forums.plex.tv/t/cant-play-some-mkv-files/935768/15 "2026-04-26T22:41:57Z")
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