Fatal error: Uncaught Error: Call to undefined function is_plugin_active() in /home/aizu330/pub/interactivebrokers.work/wp/wp-content/plugins/rich-table-of-content/functions.php:519 Stack trace: #0 /home/aizu330/pub/interactivebrokers.work/wp/wp-content/plugins/rich-table-of-content/functions.php(698): rtoc_get_index('<p><span style=...') #1 /home/aizu330/pub/interactivebrokers.work/wp/wp-includes/class-wp-hook.php(324): rtoc_switch_mokuji('<p><span style=...') #2 /home/aizu330/pub/interactivebrokers.work/wp/wp-includes/plugin.php(205): WP_Hook->apply_filters('<p><span style=...', Array) #3 /home/aizu330/pub/interactivebrokers.work/wp/wp-includes/formatting.php(3965): apply_filters('the_content', '\r\n\r\n<span style...') #4 /home/aizu330/pub/interactivebrokers.work/wp/wp-includes/class-wp-hook.php(324): wp_trim_excerpt('\r\n\r\n<span style...', Object(WP_Post)) #5 /home/aizu330/pub/interactivebrokers.work/wp/wp-includes/plugin.php(205): WP_Hook->apply_filters('', Array) #6 /home/aizu330/pub/interactivebrokers.work/wp/wp- in /home/aizu330/pub/interactivebrokers.work/wp/wp-content/plugins/rich-table-of-content/functions.php on line 519