Finally, I solved the problem by reinstalling JDK. But after starting server and connecting in NetBeans, the compilation of Empty Bot failed with following exception:

PogamutJMXException[UT2004BotEmptyBot1: Error seting up JMX name of the agent. (caused by: Error during JMX initialization.)]
at cz.cuni.amis.pogamut.ut2004.bot.impl.UT2004Bot.initCommandRequested(UT2004Bot.java:258)
.....
Exception in thread "main" ComponentCantStartException[UT2004BotEmptyBot1: Can't start Probably game server is not running, or bad address. (caused by: BusAwareCountDownLatch: Interrupted because bus was stopped (fatal error, or watched component stopped) while waiting on the latch.)]
ComponentCantStartException[UT2004BotEmptyBot1: Can't start Probably game server is not running, or bad address. (caused by: BusAwareCountDownLatch: Interrupted because bus was stopped (fatal error, or watched component stopped) while waiting on the latch.)]

But game server is running and NetBeans client seems to be connected properly.

Any idea would be very helpful.

How did you initialize the server ? Did you run a dedicated server by a console command, or a server through UT2004 GUI? Do you use a firewall? A firewall might be blocking Java to connect to localhost.
Also check the ports that are used for bot connections. The ports are pasted in a server console window when the server is completely initialized. Default prots are 3000 for bot connection and 3001 for control connection.

This is probably caused either by server not initialized properly or a firewall setting preventing the connection.

best,
michal

Thank you for your response. But I am sorry for not describing the problem properly. I am following the tutorial which means I run startGamebotsDMServer.bat in System directory which outputs: "...BotServerPort: 3000, ControlServerPort 3001... START MATCH...."

After connecting to ut://127.0.0.1:3001 in NetBeans, I started UT2004 GUI and typed "open 127.0.0.1" which succeeded and in the map in NetBeans the Player showed up. IMO this is the evidence of network communication between server and NetBeans client.

I am also able to "Connect Native Bot" but unable to connect "Pogamut bots" because of the run-time error mentioned above. Even though it seems that JRE and server are somehow communicating, I stopped the firewall but it didn't help. Maybe some internal Windows 7 application is causing the problem.

greetings, Lukas

Is there any way how to parametrize the server to be listening at different ports? This could help.

Oh, I just noticed the problem of setting different than default ports has been solved in this forum. However, this also did not help.