I was trying to throw together a mutator that would remove the corona effect from the end of the flashlights and could not get it appearing in the mutator list. I jumped back to the hello world example to figure out what I was doing wrong and can't get that to appear in the mutator list either. I've got it added under edit packages in Killing floor.ini, it compiles through fine, and the .int file also generates correctly. Still no luck though.