Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, function "wc_generator_tag" not found or invalid function name in /var/www/ond/wp-includes/class-wp-hook.php:341 Stack trace: #0 /var/www/ond/wp-includes/plugin.php(205): WP_Hook->apply_filters() #1 /var/www/ond/wp-includes/general-template.php(5225): apply_filters() #2 /var/www/ond/wp-includes/general-template.php(5137): get_the_generator() #3 /var/www/ond/wp-includes/general-template.php(5114): the_generator() #4 /var/www/ond/wp-includes/class-wp-hook.php(341): wp_generator() #5 /var/www/ond/wp-includes/class-wp-hook.php(365): WP_Hook->apply_filters() #6 /var/www/ond/wp-includes/plugin.php(522): WP_Hook->do_action() #7 /var/www/ond/wp-includes/general-template.php(3197): do_action() #8 /var/www/ond/wp-content/themes/generatepress/header.php(16): wp_head() #9 /var/www/ond/wp-includes/template.php(814): require_once('...') #10 /var/www/ond/wp-includes/template.php(749): load_template() #11 /var/www/ond/wp-includes/general-template.php(48): locate_template() #12 /var/www/ond/wp-content/themes/generatepress/functions.php(281): get_header() #13 /var/www/ond/wp-settings.php(710): include('...') #14 /var/www/ond/wp-config.php(33): require_once('...') #15 /var/www/ond/wp-load.php(50): require_once('...') #16 /var/www/ond/wp-blog-header.php(13): require_once('...') #17 /var/www/ond/index.php(17): require('...') #18 {main} thrown in /var/www/ond/wp-includes/class-wp-hook.php on line 341