Fatal error: Uncaught Error: Call to undefined function get_user_by() in /www/htdocs/w00907a7/mpu-konkret.de/wp-includes/user.php:1930 Stack trace: #0 /www/htdocs/w00907a7/mpu-konkret.de/wp-content/plugins/digimember/system/helper/wordpress.php(261): email_exists('simonewanzlick@...') #1 /www/htdocs/w00907a7/mpu-konkret.de/wp-content/plugins/digimember/application/library/autoresponder_handler/autoresponder_handler.php(1020): ncore_getUserIdByEmail('simonewanzlick@...') #2 /www/htdocs/w00907a7/mpu-konkret.de/wp-content/plugins/digimember/application/library/autoresponder_handler/autoresponder_handler.php(237): digimember_AutoresponderHandlerLib->_subscribe(Object(stdClass), Object(stdClass)) #3 /www/htdocs/w00907a7/mpu-konkret.de/wp-content/plugins/digimember/application/model/queue/ipn_out.php(42): digimember_AutoresponderHandlerLib->subscribeForOrder(Object(stdClass)) #4 /www/htdocs/w00907a7/mpu-konkret.de/wp-content/plugins/digimember/system/model/queue/base.php(23): digimember_IpnOutQueue->process(Object(stdClass)) #5 in /www/htdocs/w00907a7/mpu-konkret.de/wp-includes/user.php on line 1930