Blood Ritual REQUIRES that your installation of Unreal 2004 be patched to at LEAST version 3355 and have the Editor's Choice Bonus Pack installed.

NOTE: After installing the Bonus Pack, you may be required to re-apply the latest patch, as the patches update files contained within the Bonus Pack. If Unreal will no longer run after installing the Bonus Pack, this is the problem and you must re-apply the patch.

Download Patches from:
http://www.unrealtournament.com/ut2004/downloads.php

Download the Bonus Pack here:
http://www.beyondunreal.com

Patches and Bonus Pack are available for Windows and Linux, but you may have to dig deeper for linux downloads.