# Conversion failed. A required codec could not be found or failed to install **URL:** \ **Category:** Plex Media Server\ **Tags:** server-linux, android-tv, plex-web, lg-webos\ **Created:** [February 25, 2026, 10:18pm UTC](https://forums.plex.tv/t/conversion-failed-a-required-codec-could-not-be-found-or-failed-to-install/936693 "2026-02-25T22:18:34Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Soong](https://avatars.discourse-cdn.com/v4/letter/s/35a633/32.png) [@Soong](https://forums.plex.tv/u/Soong)\ **Post date:** [February 25, 2026, 10:18pm UTC](https://forums.plex.tv/t/conversion-failed-a-required-codec-could-not-be-found-or-failed-to-install/936693/1 "2026-02-25T22:18:34Z")
I have a TrueNAS server and it’s been running Plex fine for years. All this time I have been downloading 1080p movies and it’s played everywhere no problems. I recently got a C5 so thought I would download some movies in 4k and with HDR10. On Web OS and on the Google TV Streamer they play fine. If I try to play from web player it says “Conversion failed. A required codec could not be found or failed to install.” and fails to play. Because it works on Web OS and Google TV Streamer I assume the server is fine. So is it something on the Player I need to adjust? It’s this NAS: [https://nas-uk.ugreen.com/products/ugreen-4-slot-m2-nvme-nas](https://nas-uk.ugreen.com/products/ugreen-4-slot-m2-nvme-nas) (i5 1235u) which I assume is fast enough for 4k? When it works it’s not transcoding but on the web player (locally) it gives that error before I can even check to see if it’s trying to play in original quality. ---
**Author:** ![Atomatth](https://sea1.discourse-cdn.com/plex/user_avatar/forums.plex.tv/atomatth/32/314355_2.png) [@Atomatth](https://forums.plex.tv/u/Atomatth)\ **Post date:** [February 25, 2026, 11:27pm UTC](https://forums.plex.tv/t/conversion-failed-a-required-codec-could-not-be-found-or-failed-to-install/936693/2 "2026-02-25T23:27:28Z")
Please download your [PMS logs](https://support.plex.tv/articles/200250417-plex-media-server-log-files/) and share the entire zip here or DM to me, please. ---
**Author:** ![Soong](https://avatars.discourse-cdn.com/v4/letter/s/35a633/32.png) [@Soong](https://forums.plex.tv/u/Soong)\ **Post date:** [February 26, 2026, 8:40am UTC](https://forums.plex.tv/t/conversion-failed-a-required-codec-could-not-be-found-or-failed-to-install/936693/3 "2026-02-26T08:40:40Z")
Thank you! Logs attached. ---
**Author:** ![Atomatth](https://sea1.discourse-cdn.com/plex/user_avatar/forums.plex.tv/atomatth/32/314355_2.png) [@Atomatth](https://forums.plex.tv/u/Atomatth)\ **Post date:** [February 26, 2026, 2:30pm UTC](https://forums.plex.tv/t/conversion-failed-a-required-codec-could-not-be-found-or-failed-to-install/936693/4 "2026-02-26T14:30:00Z")
Something is wrong with your network configuration within your docker container/environment. Your logs are flooded with network failures. This is likely the issue and why you cannot acquire the required codec to transcode your files. Once you sort your network issues out, you should be go to go. ---
**Author:** ![Soong](https://avatars.discourse-cdn.com/v4/letter/s/35a633/32.png) [@Soong](https://forums.plex.tv/u/Soong)\ **Post date:** [February 26, 2026, 2:48pm UTC](https://forums.plex.tv/t/conversion-failed-a-required-codec-could-not-be-found-or-failed-to-install/936693/6 "2026-02-26T14:48:06Z")
Is it this which is the issue? Feb 26, 2026 03:43:10.554 [140307896744760] ERROR - Error parsing allowedNetworks entry ’ 192.168.11.0 24’: Invalid argument [system:22] If not which filename is it I need to look in to see the error? Thanks. ---
**Author:** ![Atomatth](https://sea1.discourse-cdn.com/plex/user_avatar/forums.plex.tv/atomatth/32/314355_2.png) [@Atomatth](https://forums.plex.tv/u/Atomatth)\ **Post date:** [February 26, 2026, 2:51pm UTC](https://forums.plex.tv/t/conversion-failed-a-required-codec-could-not-be-found-or-failed-to-install/936693/7 "2026-02-26T14:51:06Z")
Server Settings \> Network ![image](https://global.discourse-cdn.com/plex/original/4X/9/c/9/9c991edd89f36b219a5d5aabac2756c7c5f2e8a2.png) You need to use the slash notation for the subnet. Also, you should really need to set anything in this setting unless you’re having issues. ---
**Author:** ![Soong](https://avatars.discourse-cdn.com/v4/letter/s/35a633/32.png) [@Soong](https://forums.plex.tv/u/Soong)\ **Post date:** [February 26, 2026, 3:17pm UTC](https://forums.plex.tv/t/conversion-failed-a-required-codec-could-not-be-found-or-failed-to-install/936693/8 "2026-02-26T15:17:38Z")
Removed all that but still get the error. I installed this through HexOS which is very much in beta and this was a long time ago now so what I’ll do is just reinstall from fresh and see if that solves it! ---
**Author:** ![Soong](https://avatars.discourse-cdn.com/v4/letter/s/35a633/32.png) [@Soong](https://forums.plex.tv/u/Soong)\ **Post date:** [March 2, 2026, 8:11am UTC](https://forums.plex.tv/t/conversion-failed-a-required-codec-could-not-be-found-or-failed-to-install/936693/9 "2026-03-02T08:11:36Z")
It turns out 1.2.24 was the issue on TrueNAS and rolling back to 1.2.16 fixed it in case anyone else sees this with the same issue. ---
**Author:** ![system](https://global.discourse-cdn.com/plex/original/3X/2/a/2acb9765406f63293d357b4ec509ec39aa28f2ad.png) [@system](https://forums.plex.tv/u/system)\ **Post date:** [May 31, 2026, 8:12am UTC](https://forums.plex.tv/t/conversion-failed-a-required-codec-could-not-be-found-or-failed-to-install/936693/10 "2026-05-31T08:12:03Z")
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