# Trailers - Playback Error: Error code: h4 (Not supported)

**URL:** <https://forums.plex.tv/t/trailers-playback-error-error-code-h4-not-supported/903358>\
**Category:** Plex Players\
**Tags:** plex-web, discover\
**Created:** [January 24, 2025, 2:38am UTC](https://forums.plex.tv/t/trailers-playback-error-error-code-h4-not-supported/903358 "2025-01-24T02:38:35Z")\
**Posts on this page:** 13\
**Page:** 1

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**Author:** ![lacer](https://avatars.discourse-cdn.com/v4/letter/l/87869e/32.png) [@lacer](https://forums.plex.tv/u/lacer)\
**Post date:** [January 24, 2025, 2:38am UTC](https://forums.plex.tv/t/trailers-playback-error-error-code-h4-not-supported/903358/1 "2025-01-24T02:38:35Z")

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Server Version#:1.41.3  
Player Version#: web  
\<If providing [server logs](https://support.plex.tv/articles/200250417-plex-media-server-log-files/) please do NOT turn on verbose logging, only [debug logging](https://support.plex.tv/articles/201643703-reporting-issues-with-plex-media-server/#toc-1) should be enabled\>

- Using the web player on the Mac server machine
- Going to Home \> Trending \> Picking any of the most watched list \> Trailer. All of them give an playback error.

Playback Error: Error code: h4 (Not supported)

I’m assuming these are web trailers that play and should play. Unsure why these trailers aren’t playing.

Unless these are just trailers that I should have locally?

thanks

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**Author:** ![awrtwenty15](https://avatars.discourse-cdn.com/v4/letter/a/67e7ee/32.png) [@awrtwenty15](https://forums.plex.tv/u/awrtwenty15)\
**Post date:** [February 2, 2025, 12:48am UTC](https://forums.plex.tv/t/trailers-playback-error-error-code-h4-not-supported/903358/2 "2025-02-02T00:48:19Z")

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I am having this same issue attempting to play trailers and they will not play. Every time I receive this same h4 error code.

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**Author:** ![lacer](https://avatars.discourse-cdn.com/v4/letter/l/87869e/32.png) [@lacer](https://forums.plex.tv/u/lacer)\
**Post date:** [February 5, 2025, 7:15pm UTC](https://forums.plex.tv/t/trailers-playback-error-error-code-h4-not-supported/903358/3 "2025-02-05T19:15:20Z")

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seems odd that there is no plex support representive Is there no support on plex?

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**Author:** ![BigWheel](https://sea1.discourse-cdn.com/plex/user_avatar/forums.plex.tv/bigwheel/32/78783_2.png) [@BigWheel](https://forums.plex.tv/u/BigWheel)\
**Post date:** [February 5, 2025, 7:56pm UTC](https://forums.plex.tv/t/trailers-playback-error-error-code-h4-not-supported/903358/4 "2025-02-05T19:56:46Z")

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what browser are you using? do you have any adblockers etc installed?

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**Author:** ![lacer](https://avatars.discourse-cdn.com/v4/letter/l/87869e/32.png) [@lacer](https://forums.plex.tv/u/lacer)\
**Post date:** [February 7, 2025, 6:43pm UTC](https://forums.plex.tv/t/trailers-playback-error-error-code-h4-not-supported/903358/5 "2025-02-07T18:43:07Z")

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thanks for the response. Using the default safari browser with no extensions/blockers.

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**Author:** ![BigWheel](https://sea1.discourse-cdn.com/plex/user_avatar/forums.plex.tv/bigwheel/32/78783_2.png) [@BigWheel](https://forums.plex.tv/u/BigWheel)\
**Post date:** [February 7, 2025, 7:31pm UTC](https://forums.plex.tv/t/trailers-playback-error-error-code-h4-not-supported/903358/6 "2025-02-07T19:31:57Z")

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Thanks for report. seems to be an issue only in Safari

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**Author:** ![tom80H](https://sea1.discourse-cdn.com/plex/user_avatar/forums.plex.tv/tom80h/32/19753_2.png) [@tom80H](https://forums.plex.tv/u/tom80H)\
**Post date:** [February 7, 2025, 7:45pm UTC](https://forums.plex.tv/t/trailers-playback-error-error-code-h4-not-supported/903358/7 "2025-02-07T19:45:48Z")

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I’ve run into this issue before.  
~~Disabling the native Safari content blocker for the Plex web app resolved it for me.~~ _[edit: I stand corrected… still not working with Discover trailers; just for trailers on my own libraries]_

@lacer : can you verify this is disabled in the website preferences of Safari?

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**Author:** ![lacer](https://avatars.discourse-cdn.com/v4/letter/l/87869e/32.png) [@lacer](https://forums.plex.tv/u/lacer)\
**Post date:** [February 7, 2025, 7:50pm UTC](https://forums.plex.tv/t/trailers-playback-error-error-code-h4-not-supported/903358/9 "2025-02-07T19:50:29Z")

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can confirm it is safari another browser doesn’t show this error

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<div class="post-metadata">

**Author:** ![lacer](https://avatars.discourse-cdn.com/v4/letter/l/87869e/32.png) [@lacer](https://forums.plex.tv/u/lacer)\
**Post date:** [February 7, 2025, 7:51pm UTC](https://forums.plex.tv/t/trailers-playback-error-error-code-h4-not-supported/903358/10 "2025-02-07T19:51:25Z")

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I’m looking under the safari \> preferences \> websites \> content blockers nothing is active. is there somewhere else to check?

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<div class="post-metadata">

**Author:** ![BigWheel](https://sea1.discourse-cdn.com/plex/user_avatar/forums.plex.tv/bigwheel/32/78783_2.png) [@BigWheel](https://forums.plex.tv/u/BigWheel)\
**Post date:** [February 7, 2025, 7:52pm UTC](https://forums.plex.tv/t/trailers-playback-error-error-code-h4-not-supported/903358/11 "2025-02-07T19:52:54Z")

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I believe they are referring to this. But I still get error

 ![Plex](https://global.discourse-cdn.com/plex/original/4X/b/d/4/bd48c58ca6c1b92b2dc10908f54757c2cf96a6a5.png)

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<div class="post-metadata">

**Author:** ![lacer](https://avatars.discourse-cdn.com/v4/letter/l/87869e/32.png) [@lacer](https://forums.plex.tv/u/lacer)\
**Post date:** [February 7, 2025, 7:55pm UTC](https://forums.plex.tv/t/trailers-playback-error-error-code-h4-not-supported/903358/13 "2025-02-07T19:55:16Z")

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edited: disabled this setting in safari Version 18.2 (20620.1.16.11.8) still receiving that error.

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<div class="post-metadata">

**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 7, 2025, 8:44pm UTC](https://forums.plex.tv/t/trailers-playback-error-error-code-h4-not-supported/903358/15 "2025-02-07T20:44:33Z")

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Thanks for reporting. This does appear to be isolated to trailers hosted by Plex (Discover or Movies & TV Shows) and Safari while using app.plex.tv or the bundled web app on your PMS. Local PMS trailers are working as expected. I changed the tag on this post to better reflect this. An internal issue has been filed. Thanks again for reporting!

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**Author:** ![system](https://global.discourse-cdn.com/plex/original/3X/2/a/2acb9765406f63293d357b4ec509ec39aa28f2ad.png) [@system](https://forums.plex.tv/u/system)\
**Post date:** [May 8, 2025, 11:43pm UTC](https://forums.plex.tv/t/trailers-playback-error-error-code-h4-not-supported/903358/18 "2025-05-08T23:43:53Z")

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