WP6.9 + Gutenberg 22.3 + TT5 > new font library admin page is empty (cannot retrieve the custom fonts set for TT5)

[Marc-pi]

Description

Gutenberg 22.3 breaks font loading
example : TT5 where the fonts have been customized (ex : Quicksand + Noto Sans)
The solution is to roll back gutenberg or inactive the Gutenberg

Step-by-step reproduction instructions

1. Set a website under WP6.9 + TT5 + customize your font for some tag (ex : H1/H2/H3 & default text)
2. Update to Gutenberg 22.3 (dec 2025)
3. Go to wp-admin/admin.php?page=gutenberg-boot-wp-admin&p=%2Ffont-list
4. Observe that the page is empty
5. Observe that on front side, the font are not loaded at all neither

Screenshots, screen recording, code snippet

see the step by step

Environment info

• WP6.9
• TT5 theme with font customization

Please confirm that you have searched existing issues in the repo.

• Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

• Yes

Please confirm which theme type you used for testing.

• Block
• Classic
• Hybrid (e.g. classic with theme.json)
• Not sure

[t-hamano]

Thanks for the reporting. I think this issue should have been resolved by the following two PRs:

• Global Fonts: Convert relative font URLs to absolute theme URLs in font-face styles #74115
• Global Fonts: Correctly convert relative font URLs to absolute theme URLs in font-face styles #74137

Can you confirm that this issue doesn't recur in the latest Gutenberg?

https://playground.wordpress.net/?gutenberg-branch=trunk

[SirLouen]

@Marc-pi how I'm supposed to go into
wp-admin/admin.php?page=gutenberg-boot-wp-admin&p=%2Ffont-list?

You mean?
/wp-admin/admin.php?page=font-library-wp-admin&p=%2Ffont-list ?

[Marc-pi]

@SirLouen

just i've this link with the gutenberg plugin active

is it a route issue ?

You mean?
/wp-admin/admin.php?page=font-library-wp-admin&p=%2Ffont-list ?

with your url pattern, i get indeed a permission issue

[Marc-pi]

@t-hamano seems it is fixed into the gutenberg trunk repo
just Gutenberg 22.3 has the issue
My test with the playground https://playground.wordpress.net/?gutenberg-branch=trunk

1. inactive gutenberg
2. set a custom font like noto-sans for the text
3. active gutenberg
4. go to the new font page : works ! (the url path @SirLouen is https://playground.wordpress.net/scope:funny-cozy-village/wp-admin/admin.php?page=font-library-wp-admin&p=%2Ffont-list)