Problem since last Update

I Can not login: Warning: Cannot modify header information - headers already sent by (output started at /www/htdocs/XXXXXXX/wp-content/themes/catch-box-child/functions.php:2) in /www/htdocs/XXXXXXX/wp-login.php on line 402 Warning: Cannot modify header information - headers already sent by (output started at /www/htdocs/XXXXXXX/wp-content/themes/catch-box-child/functions.php:2) in /www/htdocs/XXXXXXX/wp-login.php on line 415 Warning: Cannot modify header information - headers already sent by (output started at /www/htdocs/XXXXXXX/wp-content/themes/catch-box-child/functions.php:2) in /www/htdocs/XXXXXXX/wp-includes/pluggable.php on line 892 Warning: Cannot modify header information - headers already sent by (output started at /www/htdocs/XXXXXXX/wp-content/themes/catch-box-child/functions.php:2) in /www/htdocs/XXXXXXX/wp-includes/pluggable.php on line 893 Warning: Cannot modify header information - headers already sent by (output started at /www/htdocs/XXXXXXX/wp-content/themes/catch-box-child /functions.php:2) in /www/htdocs/XXXXXXX/wp-includes/pluggable.php on line 894 And Wordpress Login says: FEHLER: Cookies sind wegen einer unerwarteten Ausgabe gesperrt. Hilfe findest du in dieser Dokumentation oder wende dich an das Support-Forum. Thank you!