'Warning: Cannot modify header'... nach update 0.21 auf 0.22

[Max Braun]

Hallo!
Nach Update von 2.0.21 auf ver 2.0.22 kann ich mich nicht mehr einloggen und es steht ganz oben im forum folgendes:

ript_name . $url); exit; } ?>
Warning: Cannot modify header information - headers already sent by (output started at /www/htdocs/v127141/forum/includes/functions.php:960) in /www/htdocs/v127141/forum/includes/sessions.php on line 254

Warning: Cannot modify header information - headers already sent by (output started at /www/htdocs/v127141/forum/includes/functions.php:960) in /www/htdocs/v127141/forum/includes/sessions.php on line 255
.'; // // That's all Folks! // ------------------------------------------------- ?>
Warning: Cannot modify header information - headers already sent by (output started at /www/htdocs/v127141/forum/includes/functions.php:960) in /www/htdocs/v127141/forum/includes/page_header.php on line 483

Warning: Cannot modify header information - headers already sent by (output started at /www/htdocs/v127141/forum/includes/functions.php:960) in /www/htdocs/v127141/forum/includes/page_header.php on line 485

Warning: Cannot modify header information - headers already sent by (output started at /www/htdocs/v127141/forum/includes/functions.php:960) in /www/htdocs/v127141/forum/includes/page_header.php on line 486

Wie kann ich das Problem beheben? Danke im voraus!

[Michael Zacher]

Was bedeutet 'headers already sent'?