Hilfe: Forum funktioniert nicht mehr

[Whitesences]

Mein phpbb Forum funktioniert nicht mehr. Es wird mir folgende Fehlermeldung angezeigt:

[phpBB Debug] PHP Notice: in file /includes/session.php on line 1024: Cannot modify header information - headers already sent by (output started at /config.php:19)
[phpBB Debug] PHP Notice: in file /includes/session.php on line 1024: Cannot modify header information - headers already sent by (output started at /config.php:19)
[phpBB Debug] PHP Notice: in file /includes/session.php on line 1024: Cannot modify header information - headers already sent by (output started at /config.php:19)
[phpBB Debug] PHP Notice: in file /includes/functions.php on line 4505: Cannot modify header information - headers already sent by (output started at /config.php:19)
[phpBB Debug] PHP Notice: in file /includes/functions.php on line 4507: Cannot modify header information - headers already sent by (output started at /config.php:19)
[phpBB Debug] PHP Notice: in file /includes/functions.php on line 4508: Cannot modify header information - headers already sent by (output started at /config.php:19)
[phpBB Debug] PHP Notice: in file /includes/functions.php on line 4509: Cannot modify header information - headers already sent by (output started at /config.php:19)

Wie kann ich diesen Fehler beheben?

LG
Whitesences (Mein Forum: http://bellaswonderworld.de/forum/)

Edit: Die Fehlermeldung tauchte auf, nachdem ich die das Mod Popup on Birthday entfernt hatte.

[Mahony]

Hallo
Suehe KB:headers_already_sent


Grüße: Mahony

[Whitesences]

Hallo
Suehe KB:headers_already_sent


Grüße: Mahony

Super vielen Dank das Problem war dank deiner Hilfeseite in ein paar Minuten gelöst. Herzlichen Dank!

LG
Whitesences