I've been having trouble installing the Fatherland mod. I know next to nothing about modding, to the extent that when I installed this mod I merely copied all of the files into the original Doomsday directory. I trusted this would work since that was basically what the readme file said. Then when I start up I get this message about two thirds of the way through the scenario loading time:
Can anybody explain what's wrong and what I should do?

Can anybody explain what's wrong and what I should do?