Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, function "add_css_js" not found or invalid function name in /home/radwave/radmusicschool.com/public_html/event/wp-includes/class-wp-hook.php:324 Stack trace: #0 /home/radwave/radmusicschool.com/public_html/event/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(NULL, Array) #1 /home/radwave/radmusicschool.com/public_html/event/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #2 /home/radwave/radmusicschool.com/public_html/event/wp-includes/script-loader.php(2272): do_action('wp_enqueue_scri...') #3 /home/radwave/radmusicschool.com/public_html/event/wp-includes/class-wp-hook.php(324): wp_enqueue_scripts('') #4 /home/radwave/radmusicschool.com/public_html/event/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(NULL, Array) #5 /home/radwave/radmusicschool.com/public_html/event/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #6 /home/radwave/radmusicschool.com/public_html/event/wp-includes/general-template.php(3064): do_action('wp_head') #7 /home/radwave/radmusicschool.com/public_html/event/wp-content/themes/radmusicschool.com/header.php(34): wp_head() #8 /home/radwave/radmusicschool.com/public_html/event/wp-includes/template.php(810): require_once('/home/radwave/r...') #9 /home/radwave/radmusicschool.com/public_html/event/wp-includes/template.php(745): load_template('/home/radwave/r...', true, Array) #10 /home/radwave/radmusicschool.com/public_html/event/wp-includes/general-template.php(48): locate_template(Array, true, true, Array) #11 /home/radwave/radmusicschool.com/public_html/event/wp-content/themes/radmusicschool.com/index.php(1): get_header() #12 /home/radwave/radmusicschool.com/public_html/event/wp-includes/template-loader.php(106): include('/home/radwave/r...') #13 /home/radwave/radmusicschool.com/public_html/event/wp-blog-header.php(19): require_once('/home/radwave/r...') #14 /home/radwave/radmusicschool.com/public_html/event/index.php(17): require('/home/radwave/r...') #15 {main} thrown in /home/radwave/radmusicschool.com/public_html/event/wp-includes/class-wp-hook.php on line 324