You've successfully installed the www.phpbb.com version of phpBB, but the $community_to_website_path does not appear to be set correctly.

See the comment block in config_default.php for an explanation of what this variable does and then overwrite its value in your local config.php

Debug Variables:
functions.php -> website ($root_path): ../community/../
functions.php -> phpBB ($phpbb_root_path): ../community/
$community_to_website_path: ../