How To Fix Fatal Error wp_print_font_faces Not Found

Ever went pulling your hair because of this error? And no matter what you activate, deactivate, nothing would help?

[24-Mar-2024 04:34:18 UTC] PHP Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, function "wp_print_font_faces" not found or invalid function name in wp-includes/class-wp-hook.php:324
Stack trace:
#0 wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#1 wp-includes/plugin.php(517): WP_Hook->do_action()
#2 wp-admin/admin-header.php(132): do_action()
#3 wp-admin/index.php(137): require_once('...')
#4 {main}
thrown in wp-includes/class-wp-hook.php on line 324

This error is caused by this file: wp-admin/includes/admin-filters.php And this happens when a WordPress update fails to delete this file.

How to Fix Fatal error: Uncaught TypeError: call_user_func_array… wp_print_font_faces

The ideal way to update WordPress is through the dashboard. But just in case you felt a little geeky-nerdy and simply overwrote the wp-admin and wp-includes folders, this method would overwrite the files and skip deleting the old, redundant files. All you have to do is to delete the file wp-admin/includes/admin-filters.php. The right way though is to delete wp-admin and wp-includes folders and then upload them afresh.

Solution for Fatal error

Delete the file wp-admin/includes/admin-filters.php because it’s not supposed to be present after the update.

Written by
Principal Security Researcher, Malcure Web Security

Shiv has worked in security and infrastructure since 2002, with hands-on experience across enterprise network security, incident response, problem coordination, triage management, Windows and Linux systems provisioning, scripting automation, Nginx, ModSecurity, reverse proxies, web application firewalls, WordPress malware removal, malicious redirect cleanup, SEO spam remediation, WP-CLI workflows, vulnerability response, and website hardening. His research informs Malcure’s malware detection, cleanup, and hardening methodology.