# A required codec could not be found or failed to install
**URL:** https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580
**Category:** Plex Media Server
**Tags:** server-windows
**Created:** [February 14, 2025, 9:17pm UTC](https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580 "2025-02-14T21:17:39Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@SteveChurch](https://forums.plex.tv/u/SteveChurch)
#### Post date: [February 14, 2025, 9:17pm UTC](https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580/1 "2025-02-14T21:17:39Z")
Was watching a movie no problem. Went to enable subtitles. Next playback attempt resulted in “Playback Error: Conversion Failed. A required codec could not be found or failed to install.” After pretty much each of the following hacks, I right-click exited the Plex systray icon and re-launched:
- Moved the .sub file away from the movie file.
- Tried disabling HDR tone mapping, then video stream transcoding.
- Tried deleting transcoder folder\Codecs.
- Tried moving transcoder folder location to c:\Windows\Temp\Plex.
- Tried uninstalling Plex Media Server and using the Microsoft Store to reinstall.
- Tried uninstalling NVidia display driver and reinstalling from scratch. NVidia driver is from 2025.02.13.
- Tried renaming “%localappdata%\Plex Media Server” and re-defining my media libraries
After each of these trial-and-error steps, the error persists with every media file I attempt to playback. In case it helps, I have almost all of my media files stored as MKV files encoded in HEVC+AAC.
Server Version#:1.41.4.9463
Player Version#: any
[Plex Media Server Logs\_2025-02-14\_16-15-38.zip](https://forums.plex.tv/uploads/short-url/8Tug5kA3x3HQ6i1n1m23IgonEHy.zip) (3.5 MB)
---
### Author:  [@DTR](https://forums.plex.tv/u/DTR)
#### Post date: [February 14, 2025, 9:40pm UTC](https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580/2 "2025-02-14T21:40:32Z")
Edit: Looks like Plex is aware of the issue: [PMS transcoding h264 broken on DS920+ - #14 by ChuckPa](https://forums.plex.tv/t/pms-transcoding-h264-broken-on-ds920/905568/14)
* * *
> Feb 14, 2025 16:10:10.202 [19112] ERROR - Codecs: Download failed: Failed to verify SHA1sum of codec!
This was just reported here as well: [Cant download new codecs : PleX](https://www.reddit.com/r/PleX/comments/1ipkl0y/cant_download_new_codecs/), and I think Plex needs to update their published hashes. After doing some digging, it looks like Plex rebuilt aac\_decoder.dll (and presumably others as well), but kept the same hashes, so the hash validation fails. E.g. when I go to [plex.tv/api/codecs/aac\_decoder?build=windows-x86\_64-standard&deviceId=1&version=e613bce-97f23d579c1001d8e9cc0d2e](https://plex.tv/api/codecs/aac_decoder?build=windows-x86_64-standard&deviceId=1&version=e613bce-97f23d579c1001d8e9cc0d2e) and compare the hashes listed there against the aac\_decoder that I have in my data directory, they match:
```plaintext
Algorithm : SHA256
Hash : 44B0540AEDB5D76381B751120ABEEE735C846698DBD4C392DE6FD55F9FFA79DB
Path : [...]\Plex Media Server\Codecs\e613bce-97f23d579c1001d8e9cc0d2e-windows-x86_64\aac_decoder.dll
Algorithm : SHA1
Hash : E144027BEC2FD322FAB5CA8732EAF7BBC2C1ED87
Path : [...]\Plex Media Server\Codecs\e613bce-97f23d579c1001d8e9cc0d2e-windows-x86_64\aac_decoder.dll
```
But when I calculate the hash from the dll downloaded, they’re different:
```plaintext
Algorithm : SHA256
Hash : 1C4AD67317676B8C8D1AD66A5277855770630DDFF7D88A48424C0E3EB873D6BC
Path : [...]\Downloads\aac_decoder.dll
Algorithm : SHA1
Hash : BE94CF89271F5E9698D0BDEC9ED814CE629F4B3A
Path : [...]\Downloads\aac_decoder.dll
```
A binary comparison shows that the files are almost identical, but have different timestamps (November 28, 2024 vs February 4, 2025):
and PDB paths:
which results in the different hash.
---
### Author:  [@ChuckPa](https://forums.plex.tv/u/ChuckPa)
#### Post date: [February 14, 2025, 10:06pm UTC](https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580/3 "2025-02-14T22:06:51Z")
## ALL:
Please give us a bit.
We’re on it now ([Plex.tv](http://Plex.tv) problem)
---
### Author:  [@JoePhelps](https://forums.plex.tv/u/JoePhelps)
#### Post date: [February 14, 2025, 10:05pm UTC](https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580/4 "2025-02-14T22:05:08Z")
Server Version#: 1.41.4.9463
Player Version#: 4.145.1
Upgraded Plex to current version today and started receiving the error above when trying to play anything in Chrome or Firefox on Windows 11.
Moderator Edit: Moved your post to this thread (the problem affects multiple platforms). @FordGuy61
---
### Author:  [@SteveChurch](https://forums.plex.tv/u/SteveChurch)
#### Post date: [February 14, 2025, 11:41pm UTC](https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580/5 "2025-02-14T23:41:32Z")
> [@DTR](#):
>
> E.g. when I go to [plex.tv/api/codecs/aac\_decoder?build=windows-x86\_64-standard&deviceId=1&version=e613bce-97f23d579c1001d8e9cc0d2e](https://plex.tv/api/codecs/aac_decoder?build=windows-x86_64-standard&deviceId=1&version=e613bce-97f23d579c1001d8e9cc0d2e) and compare the hashes listed there against the aac\_decoder that I have in my data directory, they match
Welp. I was hoping this fix would be measured in minutes, maybe hours. Doesn’t look like that’s going to happen. Would you care to attach a copy of your November 28, 2024 aac\_decoder.dll that I could paste into my Plex Media Server application directory till the Plex publishers get their poop in a group wrt this library hash mismatch?
---
### Author:  [@DTR](https://forums.plex.tv/u/DTR)
#### Post date: [February 14, 2025, 11:48pm UTC](https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580/6 "2025-02-14T23:48:41Z")
Here’s the contents of my “Codecs\e613bce-97f23d579c1001d8e9cc0d2e-windows-x86\_64” folder:
[Codecs.zip](https://forums.plex.tv/uploads/short-url/r86YJYBLA5OYq0d578C2Z8DSymA.zip) (5.2 MB)
---
### Author:  [@SteveChurch](https://forums.plex.tv/u/SteveChurch)
#### Post date: [February 15, 2025, 12:16am UTC](https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580/7 "2025-02-15T00:16:07Z")
Thanks! That would’ve been awesome if it’d worked. Guess I’ll just hurry up and wait, blast it.
---
### Author:  [@techkn8](https://forums.plex.tv/u/techkn8)
#### Post date: [February 15, 2025, 12:31am UTC](https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580/8 "2025-02-15T00:31:09Z")
I thought I was loosing my mind cuz I dont even have a Codecs folder !!
---
### Author:  [@SteveChurch](https://forums.plex.tv/u/SteveChurch)
#### Post date: [February 15, 2025, 12:34am UTC](https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580/9 "2025-02-15T00:34:14Z")
If your Plex server is on Windows it’d be in “%localappdata%\Plex Media Server”. But you could still be losing your mind though.
---
### Author:  [@ChuckPa](https://forums.plex.tv/u/ChuckPa)
#### Post date: [February 15, 2025, 12:36am UTC](https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580/10 "2025-02-15T00:36:50Z")
## FOLKS:
Making progress here.
So far, I’ve tested 3 different installations with success on 1.41.3 and 1.41.4
My procedure:
1. Stop PMS
2. Rename `Codecs` → `Codecs-old`
3. Start PMS
4. Play back one thing which needs a codec to confirm
---
### Author:  [@SteveChurch](https://forums.plex.tv/u/SteveChurch)
#### Post date: [February 15, 2025, 1:05am UTC](https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580/11 "2025-02-15T01:05:51Z")
Failed for me on 1.41.4.9463. Exited the PMS systray app. Removed “%localappdata%\Plex Media Server\Codecs”. Relaunched Plex Media Server. Played back a movie with an AAC audio track. “%localappdata%\Plex Media Server\Codecs\e613bce-97f23d579c1001d8e9cc0d2e-windows-x86\_64” reappeared but is empty. Codecs still aren’t downloading.
---
### Author:  [@ChuckPa](https://forums.plex.tv/u/ChuckPa)
#### Post date: [February 15, 2025, 1:08am UTC](https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580/12 "2025-02-15T01:08:27Z")
@SteveChurch
Thanks for reporting.
Having success on other platforms so we’re not there yet.
Sorry for the troubles.
---
### Author:  [@dscharalampidis](https://forums.plex.tv/u/dscharalampidis)
#### Post date: [February 15, 2025, 1:20am UTC](https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580/13 "2025-02-15T01:20:19Z")
@chuckpa This did not work for me on Plex Media Server v1.41.4.9463-630c9f557
```auto
Feb 15, 2025 02:16:15.732 [131167386872632] INFO - [Req#4c/Transcode] CodecManager: obtaining decoder 'h264'
Feb 15, 2025 02:16:15.732 [131167386872632] DEBUG - [Req#4c/Transcode/HCl#2c] HTTP requesting GET https://plex.tv/api/codecs/h264_decoder?build=linux-x86_64-standard&deviceId=32b9a9b7-9208-4980-ad6f-e31c722ff872&oldestPreviousVersi
Feb 15, 2025 02:16:15.825 [131167428815672] DEBUG - [HttpClient/HCl#2c] HTTP/1.1 (0.1s) 200 response from GET https://plex.tv/api/codecs/h264_decoder?build=linux-x86_64-standard&deviceId=32b9a9b7-9208-4980-ad6f-e31c722ff872&oldestP
Feb 15, 2025 02:16:15.825 [131167424621368] DEBUG - [Req#4c/Transcode/GetFile/HCl#2d] HTTP requesting GET https://downloads.plex.tv/codecs/e613bce-97f23d579c1001d8e9cc0d2e/linux-x86_64-standard/libh264_decoder.so
Feb 15, 2025 02:16:15.828 [131167302986552] DEBUG - [PubsubServerManager/process/HCl#2e] HTTP requesting GET https://plex.tv/services/pubsub/servers
Feb 15, 2025 02:16:15.890 [131167428815672] DEBUG - [HttpClient/HCl#2e] HTTP/1.1 (0.1s) 200 response from GET https://plex.tv/services/pubsub/servers (reused)
Feb 15, 2025 02:16:16.004 [131167428815672] DEBUG - [HttpClient/HCl#2d] HTTP/2.0 (0.2s) 200 response from GET https://downloads.plex.tv/codecs/e613bce-97f23d579c1001d8e9cc0d2e/linux-x86_64-standard/libh264_decoder.so (reused)
Feb 15, 2025 02:16:16.028 [131167424621368] ERROR - [Req#4c/Transcode] Codecs: Download failed: Failed to verify SHA1sum of codec!
Feb 15, 2025 02:16:16.028 [131167386872632] ERROR - [Req#4c/Transcode] Error configuring transcoder: Decoder install failed: h264
Feb 15, 2025 02:16:16.028 [131167386872632] DEBUG - [Req#4c/Transcode] Streaming Resource: Terminating session 0x774bcbc96938:hl56qze0lni20sidzok4hmpe which is using 695kbps of WAN bandwidth. Used is now 0kbps
Feb 15, 2025 02:16:16.028 [131167386872632] DEBUG - [Req#4c/Transcode] Streaming Resource: Terminated session 0x774bcbc96938:hl56qze0lni20sidzok4hmpe with reason Conversion failed. A required codec could not be found or failed to i
Feb 15, 2025 02:16:16.028 [131167298792248] DEBUG - [Req#4c/Transcode] Killing job.
```
Trying manually the:
```auto
https://plex.tv/api/codecs/h264_decoder?build=linux-x86_64-standard&deviceId=32b9a9b7-9208-4980-ad6f-e31c722ff872&oldestPreviousVersion=1%2E32%2E6%2E7468-07e0d4a7e&version=e613bce-97f23d579c1001d8e9cc0d2e
```
returns:
```auto
```
Trying manually the:
```auto
https://downloads.plex.tv/codecs/e613bce-97f23d579c1001d8e9cc0d2e/linux-x86_64-standard/libh264_decoder.so
```
Downloads the file with SHA1sum:
```auto
b76b41c246404987d58680672e6da266ad214f13
```
I hope this helps.
---
### Author:  [@ethanmaresca](https://forums.plex.tv/u/ethanmaresca)
#### Post date: [February 15, 2025, 1:44am UTC](https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580/14 "2025-02-15T01:44:38Z")
Same problem, I don’t even have a codecs folder
---
### Author:  [@peter\_972](https://forums.plex.tv/u/peter_972)
#### Post date: [February 15, 2025, 2:09am UTC](https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580/15 "2025-02-15T02:09:34Z")
Fresh install on windows 11 also has no codecs, presuming it’s related. Transcoding to web browser is sadly ~1mbps.
---
### Author:  [@Unicron0827](https://forums.plex.tv/u/Unicron0827)
#### Post date: [February 15, 2025, 4:11am UTC](https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580/16 "2025-02-15T04:11:48Z")
You sir are a hero. Ive been tearing my hair ouit for a few hours now. This got me back up and running until they fix whatevers messed up on the backend
---
### Author:  [@DTR](https://forums.plex.tv/u/DTR)
#### Post date: [February 15, 2025, 4:21am UTC](https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580/17 "2025-02-15T04:21:26Z")
Glad it worked! Curious that the same thing didn’t seem to work for @SteveChurch though.
---
### Author:  [@Plexguy24](https://forums.plex.tv/u/Plexguy24)
#### Post date: [February 15, 2025, 4:48am UTC](https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580/18 "2025-02-15T04:48:27Z")
Completed Windows 11 2-2025 cumulative updates, defender definitions, and .net desktop runtime 8.0.13.
Also ran updates for plex media server and experiece the same thing. Live TV from HD homerun tuner and media library files are failing to playback. Also confirmed removing the codec folder in appdata did not work. Folder is recreated however is not filled with anything.
I’d be happy to share any logs if they’d help.
---
### Author:  [@FordGuy61](https://forums.plex.tv/u/FordGuy61)
#### Post date: [February 15, 2025, 6:58am UTC](https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580/19 "2025-02-15T06:58:44Z")
@Plexguy24
It is a Plex problem. Nothing you can do but wait for the fix.
---
### Author:  [@Fryer6900](https://forums.plex.tv/u/Fryer6900)
#### Post date: [February 15, 2025, 8:07am UTC](https://forums.plex.tv/t/a-required-codec-could-not-be-found-or-failed-to-install/905580/20 "2025-02-15T08:07:41Z")
Thanks for the link. Fixed my issues until they permanently fix the problem. Now my kid won’t go crazy lol
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