Fatal error: Uncaught Error: Call to undefined function wp_get_block_css_selector() in /wp-includes/class-wp-theme-json.php:904 Stack trace: #0 /wp-includes/class-wp-theme-json.php(607): WP_Theme_JSON::get_blocks_metadata() #1 /wp-includes/class-wp-theme-json-resolver.php(562): WP_Theme_JSON->__construct() #2 /wp-includes/script-loader.php(3232): WP_Theme_JSON_Resolver::get_merged_data() #3 /wp-includes/script-loader.php(3428): {closure}() #4 /wp-includes/class-wp-hook.php(308): {closure}('') #5 /wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters(NULL, Array) #6 /wp-includes/plugin.php(517): WP_Hook->do_action(Array) #7 /wp-settings.php(645): do_action('wp_loaded') #8 /wp-config.php(96): require_once('/wp-settings.ph...') #9 /wp-load.php(50): require_once('/wp-config.php') #10 /wp-blog-header.php(13): require_once('/wp-load.php') #11 /index.php(17): require('/wp-blog-header...') #12 {main} thrown in /wp-includes/class-wp-theme-json.php on line 904