As some of you hearded before, Epic Games is shutting down the UT2004 Master Server:
https://www.epicgames.com/site/de/news/epic-is-turning-off-online-services-and-servers-for-some-older-games
There is a new community Master Server provided by OpenSpy.
To use Openspy, you have to make some small adjustments in your UT2004.ini
Instructions to do so can be found here:
https://ut2004serverlist.com
The Quick Way (in-game) to update
In the game, open the console (~ key) and paste the following command and run it:
set IpDrv.MasterServerLink MasterServerList ((Address="utmaster.openspy.net",Port=28902))
and relaunch the game. This will update your game automatically.
The Longer Way to update
Browse on your computer to where your copy of Unreal Tournament 2004 is installed.
GOG Games Installs (default) to: C:\GOG Games\Unreal Tournament 2004
Original CD/DVD Installs to: C:\UT2004\
Steam Installs to C:\Program Files (x86)\Steam\steamapps\common\Unreal Tournament 2004
Go to the “System” folder inside of the UT2004 install. You’ll find a file called UT2004.ini
Open the file and scroll down to UT2004.ini and open it with notepad.
Search the file until you come to this section:
Delete the second MasterServerList line, and change the first line, so that it looks like this.
MasterServerList=(Address="utmaster.openspy.net",Port=28902)
For details about Openspy you can have a look on
http://beta.openspy.net/en/
All Fair-Gamers UT2004 Servers were migrated to OpenSpy.
You can also add the servers your favorites.