You need to enter all Packages you are using in you servers UT2004.ini, section [Engine.GameEngine]. In your case the following line is missing missing:
The good news is your server should now deliver the mod to the clients. The bad news is, it'll be awfully slow. So consider to setup a redirect, either by using ut-files.com
or setting up your very own redirect server if you intend to run the server in a LAN only environment.
Thread moved to server category...