Настройка форума phpbb3

Купили форум, перенес на свой хостинг, вылазит:

[phpBB Debug] PHP Warning: in file [ROOT]/includes/session.php on line 1035: Cannot modify header information - headers already sent by (output started at [ROOT]/includes/functions_content.php:1)

[phpBB Debug] PHP Warning: in file [ROOT]/includes/session.php on line 1035: Cannot modify header information - headers already sent by (output started at [ROOT]/includes/functions_content.php:1)

[phpBB Debug] PHP Warning: in file [ROOT]/includes/session.php on line 1035: Cannot modify header information - headers already sent by (output started at [ROOT]/includes/functions_content.php:1)

[phpBB Debug] PHP Warning: in file [ROOT]/includes/functions.php on line 4697: Cannot modify header information - headers already sent by (output started at [ROOT]/includes/functions_content.php:1)

[phpBB Debug] PHP Warning: in file [ROOT]/includes/functions.php on line 4699: Cannot modify header information - headers already sent by (output started at [ROOT]/includes/functions_content.php:1)

[phpBB Debug] PHP Warning: in file [ROOT]/includes/functions.php on line 4700: Cannot modify header information - headers already sent by (output started at [ROOT]/includes/functions_content.php:1)

[phpBB Debug] PHP Warning: in file [ROOT]/includes/functions.php on line 4701: Cannot modify header information - headers already sent by (output started at [ROOT]/includes/functions_content.php:1)

И не работает сама навигация. Так же не могу залониниться и поменять настройки путей.

Подозреваю что в переданом архиве также не хватает файлов

Нужно:

Настроить форум так чтобы все работало в фронте.

Опыт обязателен