Fatal error: Uncaught Error: Call to undefined function register_block_type() in /var/www/vhosts/cbzbfcgx.host214.checkdomain.de/htdocs/wp-content/plugins/ninja-forms/blocks/bootstrap.php:21 Stack trace: #0 /var/www/vhosts/cbzbfcgx.host214.checkdomain.de/htdocs/wp-includes/class-wp-hook.php(286): Ninja_Forms::{closure}('') #1 /var/www/vhosts/cbzbfcgx.host214.checkdomain.de/htdocs/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters(true, Array) #2 /var/www/vhosts/cbzbfcgx.host214.checkdomain.de/htdocs/wp-includes/plugin.php(453): WP_Hook->do_action(Array) #3 /var/www/vhosts/cbzbfcgx.host214.checkdomain.de/htdocs/wp-settings.php(450): do_action('init') #4 /var/www/vhosts/cbzbfcgx.host214.checkdomain.de/htdocs/wp-config.php(116): require_once('/var/www/vhosts...') #5 /var/www/vhosts/cbzbfcgx.host214.checkdomain.de/htdocs/wp-load.php(37): require_once('/var/www/vhosts...') #6 /var/www/vhosts/cbzbfcgx.host214.checkdomain.de/htdocs/wp-blog-header.php(13): require_once('/var/www/vhosts...') #7 /var/www/vhosts/cbzbfcgx.hos in /var/www/vhosts/cbzbfcgx.host214.checkdomain.de/htdocs/wp-content/plugins/ninja-forms/blocks/bootstrap.php on line 21