Fatal error: Uncaught Error: Class "WP_Block_Supports" not found in /usr/home/instytutoka/domains/laser2rt.pl/public_html/wp-includes/block-supports/custom-classname.php:61
Stack trace:
#0 {main}
  thrown in /usr/home/instytutoka/domains/laser2rt.pl/public_html/wp-includes/block-supports/custom-classname.php on line 61