Fatal error: Uncaught TypeError: substr(): Argument #1 ($string) must be of type string, int given in /mnt/web405/e2/53/510654853/htdocs/wp/wp-content/plugins/wp-rocket/inc/ThirdParty/Plugins/CDN/Cloudflare.php:562
Stack trace:
#0 /mnt/web405/e2/53/510654853/htdocs/wp/wp-content/plugins/wp-rocket/inc/ThirdParty/Plugins/CDN/Cloudflare.php(562): substr()
#1 /mnt/web405/e2/53/510654853/htdocs/wp/wp-content/plugins/wp-rocket/inc/ThirdParty/Plugins/CDN/Cloudflare.php(535): WP_Rocket\ThirdParty\Plugins\CDN\Cloudflare->unregister_callback()
#2 /mnt/web405/e2/53/510654853/htdocs/wp/wp-includes/class-wp-hook.php(353): WP_Rocket\ThirdParty\Plugins\CDN\Cloudflare->unregister_cloudflare_clean_on_post()
#3 /mnt/web405/e2/53/510654853/htdocs/wp/wp-includes/class-wp-hook.php(377): WP_Hook->apply_filters()
#4 /mnt/web405/e2/53/510654853/htdocs/wp/wp-includes/plugin.php(523): WP_Hook->do_action()
#5 /mnt/web405/e2/53/510654853/htdocs/wp/wp-settings.php(779): do_action()
#6 /mnt/web405/e2/53/510654853/htdocs/wp/wp-config.php(94): require_once('...')
#7 /mnt/web405/e2/53/510654853/htdocs/wp/wp-load.php(50): require_once('...')
#8 /mnt/web405/e2/53/510654853/htdocs/wp/wp-blog-header.php(13): require_once('...')
#9 /mnt/web405/e2/53/510654853/htdocs/wp/index.php(17): require('...')
#10 {main}
  thrown in /mnt/web405/e2/53/510654853/htdocs/wp/wp-content/plugins/wp-rocket/inc/ThirdParty/Plugins/CDN/Cloudflare.php on line 562