How do I put new maps into my PC game?

Question

I downloaded some new maps and i can't seem to get them to work. I do what they tell me to do in the zipped readme file. I created an Add on folder and then created a folder with-in there. I put all the files into that folder then run the game. I see the map in the menu but when i get to the option to launch the game, the game program goes down and it says unable to load mission.lvl? Anyone know what i'm doing wrong and have some more tips?

Answer 1

It would help if you told us what game it was... That would be nice.