Fatal error: Uncaught Error: Call to undefined function wp_is_block_theme() in /home/liaison/www/umeda/wp-content/plugins/ultimate-addons-for-gutenberg/classes/class-uagb-front-assets.php:136 Stack trace: #0 /home/liaison/www/umeda/wp-includes/class-wp-hook.php(303): UAGB_Front_Assets->enqueue_asset_files('') #1 /home/liaison/www/umeda/wp-includes/class-wp-hook.php(327): WP_Hook->apply_filters(NULL, Array) #2 /home/liaison/www/umeda/wp-includes/plugin.php(470): WP_Hook->do_action(Array) #3 /home/liaison/www/umeda/wp-includes/script-loader.php(2083): do_action('wp_enqueue_scri...') #4 /home/liaison/www/umeda/wp-includes/class-wp-hook.php(303): wp_enqueue_scripts('') #5 /home/liaison/www/umeda/wp-includes/class-wp-hook.php(327): WP_Hook->apply_filters(NULL, Array) #6 /home/liaison/www/umeda/wp-includes/plugin.php(470): WP_Hook->do_action(Array) #7 /home/liaison/www/umeda/wp-includes/general-template.php(3015): do_action('wp_head') #8 /home/liaison/www/umeda/wp-content/themes/onepress/header.php(30): wp_head() #9 /home/liais in /home/liaison/www/umeda/wp-content/plugins/ultimate-addons-for-gutenberg/classes/class-uagb-front-assets.php on line 136