Thread:Project:Support desk/Problem opening WebStart.php/reply (11)

That is the problem! MediaWiki needs at least PHP 5.3.xx. Your PHP version is too old.

You should use current versions, that is PHP 5.3 or newer, preferably 5.5. For MySQL at least version 5.1 is needed and MediaWiki will work without problems with everything up to and including MySQL 5.5. MySQL 5.6 might work, but has not yet been thoroughly tested.