FYI, I"m getting
[phpBB Debug] PHP Notice: in file /includes/functions.php on line 3730: Cannot modify header information - headers already sent by (output started at /language/en/common.php:1)
[phpBB Debug] PHP Notice: in file /includes/functions.php on line 3732: Cannot modify header information - headers already sent by (output started at /language/en/common.php:1)
[phpBB Debug] PHP Notice: in file /includes/functions.php on line 3733: Cannot modify header information - headers already sent by (output started at /language/en/common.php:1)
[phpBB Debug] PHP Notice: in file /includes/functions.php on line 3734: Cannot modify header information - headers already sent by (output started at /language/en/common.php:1)
I have tried to install it twice now and made sure not to have any extra spaces. But I don't know php well enough to know if the install instructions have extra spaces in the code or not.
Anyway, I'm going to uninstall it and wait till the stable release.