t of valid mime-types for each file extension can be provided to
	 * the 'upload_mimes' filter.
	 *
	 * @since 6.5.0
	 *
	 * @access private
	 *
	 * @return array A collection of mime types keyed by file extension.
	 */
	public static function get_allowed_font_mime_types() {
		$php_7_ttf_mime_type = PHP_VERSION_ID >= 70300 ? 'application/font-sfnt' : 'application/x-font-ttf';

		return array(
			'otf'   => 'application/vnd.ms-opentype',
			'ttf'   => PHP_VERSION_ID >= 70400 ? 'font/sfnt' : $php_7_ttf_mime_type,
			'woff'  => PHP_VERSION_ID >= 80112 ? 'font/woff' : 'application/font-woff',
			'woff2' => PHP_VERSION_ID >= 80112 ? 'font/woff2' : 'application/font-woff2',
		);
	}
}
<br />
<b>Fatal error</b>:  Uncaught Error: Class 'WP_Font_Utils' not found in /home/sportuga/public_html/wp-includes/fonts/class-wp-font-collection.php:222
Stack trace:
#0 /home/sportuga/public_html/wp-includes/fonts/class-wp-font-collection.php(74): WP_Font_Collection-&gt;sanitize_and_validate_data(Array, Array)
#1 /home/sportuga/public_html/wp-includes/fonts/class-wp-font-library.php(47): WP_Font_Collection-&gt;__construct('google-fonts', Array)
#2 /home/sportuga/public_html/wp-includes/fonts.php(79): WP_Font_Library-&gt;register_font_collection('google-fonts', Array)
#3 /home/sportuga/public_html/wp-includes/fonts.php(270): wp_register_font_collection('google-fonts', Array)
#4 /home/sportuga/public_html/wp-includes/class-wp-hook.php(324): _wp_register_default_font_collections('')
#5 /home/sportuga/public_html/wp-includes/class-wp-hook.php(348): WP_Hook-&gt;apply_filters(NULL, Array)
#6 /home/sportuga/public_html/wp-includes/plugin.php(517): WP_Hook-&gt;do_action(Array)
#7 /home/sportuga/public_html/wp-settings.php(695): do_action('init')
#8 /home/ in <b>/home/sportuga/public_html/wp-includes/fonts/class-wp-font-collection.php</b> on line <b>222</b><br />