Well, the game works perfectly fine in single-player mode for me, but, I'm having trouble accessing the Zombie and Multiplayer modes. Now, I am fully aware of the solutions to my problem posted on the first page of this thread; however, I'm a bit confused. I downloaded the ciosx_rev20 installer from a link posted here. I know that will install cios38 rev 20b. I keep seeing cIOS 250 , however. I have cios38 rev 17 and I don't want to update just yet. Will the ciosx_rev20b installer do the same thing as downloading the cISO 250  wad and installing it with WAD Manager? These two have somewhat confused me. Thanks in advance.