Alien Swarm not starting (no error)

[TTsura]

I followed the instructions of where to put Alien Swarm inside my UT2k4 folder, but whenever I start the game, a window pops up for a split second, then closes. Perhaps I made a mistake? Regular UT works fine, and it's the ECE. How do I use the .mod file to install it? Maybe that would fix things.

[Moses2k]

Typical reason is you may need patch 3369 to UT2k4? There's probably other threads in this forum to help until someone else comes along to comment.

[reemulmyu]

also play ut any match type after you have installed swarm it generates a ini file which might not be present