PHP “Deprecated” notice on PHP8.3

Hello,

My WordPress network (multisite) is running on server with PHP 8.3 and on /wp-admin/network/update-core.php page I get this PHP notice/warning:

[24-Sep-2025 06:21:32 UTC] PHP Deprecated:
preg_replace():
Passing null to parameter #3 ($subject) of type array|string is deprecated
in ./wp-includes/kses.php on line 1807

I’ve traced the issue to $notice value in UpdraftPlus_Admin->core_upgrade_preamble() method in admin.php file on line #1215.

Please fix this by forcing STRING value instead of possible NULL.

My temporary fix:
Currently I’m fixing the issue with a must-use plugin with this code:

add_filter( 'updraftplus_autobackup_blurb', function( $notice ) {
	return (string) $notice;
}, 999 );

Thank you!

• This topic was modified 2 months, 2 weeks ago by WebMan Design | Oliver Juhas.