I'm using a forum on my site. I uploaded ALL files into the right directory and I succesfully installed it but whenever I try to open index.php in the subdirectory "admin" I get the following error:

Warning: open_basedir restriction in effect. File is in wrong directory in /clans/metalgear/forum/admin/global.php on line 2
Fatal error: Failed opening required './../_data.inc.php' (include_path='.:/usr/share/pear') in /clans/metalgear/forum/admin/global.php on line 2

What does it mean and what should I do about it????