Errors after WP5.3 update

After upgrading to WP5.3, some errors are shown on the “Create new …” page:

Warning: strlen() expects parameter 1 to be string, object given in /home/www/wordpress/wp-includes/formatting.php on line 3380

Warning: strlen() expects parameter 1 to be string, object given in /home/www/wordpress/wp-includes/formatting.php on line 3380

Warning: strlen() expects parameter 1 to be string, object given in /home/www/wordpress/wp-includes/formatting.php on line 3380

Warning: Cannot modify header information - headers already sent by (output started at /home/www/wordpress/wp-includes/formatting.php:3380) in /home/www/wordpress/wp-admin/admin-header.php on line 9

I’m pretty sure, that the issue is with Graphene, since deactivating all Plugins doesn’t fix the issue, but changing the theme does.
Also the errors only appear in the block editor. When switching to the classig editor via the Classic Editor plugin, everthing is fine.
The rest of the website looks just fine, but I’d still be glad if this was fixed.
Looking forward to your response ??

• This topic was modified 5 years, 3 months ago by hirschheissich.
• This topic was modified 5 years, 3 months ago by hirschheissich.