# Network page edition : Class “PressbooksMix\\Assets” not found

**URL:** <https://pressbooks.community/t/network-page-edition-class-pressbooksmix-assets-not-found/4609>\
**Category:** Troubleshooting Installation/Upgrades\
**Created:** [June 11, 2026, 8:22am UTC](https://pressbooks.community/t/network-page-edition-class-pressbooksmix-assets-not-found/4609 "2026-06-11T08:22:22Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![RmbxCh](https://pressbooks.community/user_avatar/pressbooks.community/rmbxch/32/1785_2.png) [@RmbxCh](https://pressbooks.community/u/RmbxCh)\
**Post date:** [June 11, 2026, 8:22am UTC](https://pressbooks.community/t/network-page-edition-class-pressbooksmix-assets-not-found/4609/1 "2026-06-11T08:22:22Z")

</div>

Hi everyone,

It’s me again 😅 I’m getting a fatal error when editing pages from Network Admin (such as “about”, “help”…) :

 ![Capture d'écran 2026-06-11 092346](https://pressbooks.community/uploads/default/original/2X/b/b139473829b0e7df6121e0a7ba61177744190e38.png)

Here’s the full notice :

`PHP Fatal error: Uncaught Error: Class “PressbooksMix\Assets” not found in /var/www/html/wp-content/themes/pressbooks-aldine/inc/filters/namespace.php:88`  
`Stack trace:`  
`#0 /var/www/html/wp-includes/class-wp-hook.php(343): Aldine\Filters\add_buttons(Array)`  
`#1 /var/www/html/wp-includes/plugin.php(205): WP_Hook->apply_filters(Array, Array)`  
`#2 /var/www/html/wp-includes/class-wp-editor.php(421): apply_filters(‘mce_external_pl…’, Array, ‘content’)`  
`#3 /var/www/html/wp-includes/class-wp-editor.php(312): _WP_Editors::editor_settings(‘content’, Array)`  
`#4 /var/www/html/wp-includes/general-template.php(3985): _WP_Editors::editor(‘La fa\xC3\xA7on la pl…’, ‘content’, Array)`  
`#5 /var/www/html/wp-admin/edit-form-advanced.php(618): wp_editor(‘La fa\xC3\xA7on la pl…’, ‘content’, Array)`  
`#6 /var/www/html/wp-admin/post.php(206): require(‘/var/www/html/w…’)`  
`#7 {main}`  
`thrown in /var/www/html/wp-content/themes/pressbooks-aldine/inc/filters/namespace.php on line 88`

I was using Aldine 1.25.2 so I updated to 1.25.3 but the error still occurs. I’m running Pressbooks 6.42.0 and Wordpress 6.9.1  
The error doesn’t seem to affect the content itself. The text appears white in the WYSIWYG editor, but it displays correctly on the front end. The issue also does not occur when editing book pages.

Could you help me troubleshoot this ?

Please let me know if I can provide any additional information.  
Charlotte

---

<div class="post-metadata">

**Author:** ![arzola](https://pressbooks.community/user_avatar/pressbooks.community/arzola/32/2290_2.png) [@arzola](https://pressbooks.community/u/arzola)\
**Post date:** [June 11, 2026, 4:32pm UTC](https://pressbooks.community/t/network-page-edition-class-pressbooksmix-assets-not-found/4609/2 "2026-06-11T16:32:36Z")

</div>

Sorry about that

We just cut a hotfix release for that build tools leftover [Release v1.25.4 · pressbooks/pressbooks-aldine · GitHub](https://github.com/pressbooks/pressbooks-aldine/releases/tag/1.25.4)

---

<div class="post-metadata">

**Author:** ![RmbxCh](https://pressbooks.community/user_avatar/pressbooks.community/rmbxch/32/1785_2.png) [@RmbxCh](https://pressbooks.community/u/RmbxCh)\
**Post date:** [June 12, 2026, 2:37pm UTC](https://pressbooks.community/t/network-page-edition-class-pressbooksmix-assets-not-found/4609/3 "2026-06-12T14:37:22Z")

</div>

Hi,

Thanks for the quick fix ! No more fatal error but i have warnings showing on the top of the WYSIWYG :

 ![image](https://pressbooks.community/uploads/default/original/2X/7/75a514aef1966ea873464223638b9769c63df587.png)

I maybe did something wrong in the update process

---

<div class="post-metadata">

**Author:** ![arzola](https://pressbooks.community/user_avatar/pressbooks.community/arzola/32/2290_2.png) [@arzola](https://pressbooks.community/u/arzola)\
**Post date:** [August 6, 2026, 11:47pm UTC](https://pressbooks.community/t/network-page-edition-class-pressbooksmix-assets-not-found/4609/4 "2026-08-06T23:47:29Z")

</div>

@RmbxCh We are very sorry about the delay on this response, we just released a new version of Pressbooks Aldine that address this, we didn’t noticed it before because this was happening only on French installations.

> **[Release v1.26.0 · pressbooks/pressbooks-aldine](https://github.com/pressbooks/pressbooks-aldine/releases/tag/1.26.0)**
>
> 1.26.0 (2026-08-06)
> Features
> 
> add contact form hooks for custom validation (#583) (39e315d)
> 
> Bug Fixes
> 
> escape editor button i18n strings to prevent TinyMCE plugin init failures (#586) (e6bb0ac)
> 
> C...

---

<div class="post-metadata">

**Author:** ![RmbxCh](https://pressbooks.community/user_avatar/pressbooks.community/rmbxch/32/1785_2.png) [@RmbxCh](https://pressbooks.community/u/RmbxCh)\
**Post date:** [August 7, 2026, 12:59pm UTC](https://pressbooks.community/t/network-page-edition-class-pressbooksmix-assets-not-found/4609/5 "2026-08-07T12:59:50Z")

</div>

No more warnings, thank you very much !