PHP User Warnung: array_keys() expects parameter 1 to be array, null given in ..../includes/functions.php (Zeile 4291)

PHP User Warnung: Invalid argument supplied for foreach() in ..../includes/functions.php (Zeile 4291)

PHP User Warnung: Cannot modify header information - headers already sent by (output started at ..../includes/class_core.php:3308) in ..../includes/functions.php (Zeile 3140)