Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, class "\WPO\WC\PDF_Invoices\Updraft_Semaphore_3_0" not found in /data03/virt76615/domeenid/www.pocophone.ee/htdocs/wp-includes/class-wp-hook.php:324 Stack trace: #0 /data03/virt76615/domeenid/www.pocophone.ee/htdocs/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(NULL, Array) #1 /data03/virt76615/domeenid/www.pocophone.ee/htdocs/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #2 /data03/virt76615/domeenid/www.pocophone.ee/htdocs/wp-settings.php(704): do_action('init') #3 /data03/virt76615/domeenid/www.pocophone.ee/htdocs/wp-config.php(101): require_once('/data03/virt766...') #4 /data03/virt76615/domeenid/www.pocophone.ee/htdocs/wp-load.php(50): require_once('/data03/virt766...') #5 /data03/virt76615/domeenid/www.pocophone.ee/htdocs/wp-blog-header.php(13): require_once('/data03/virt766...') #6 /data03/virt76615/domeenid/www.pocophone.ee/htdocs/index.php(17): require('/data03/virt766...') #7 {main} thrown in /data03/virt76615/domeenid/www.pocophone.ee/htdocs/wp-includes/class-wp-hook.php on line 324