I've been trying to add new units to PTW scenarios, but I keep getting this error. The link goes to a picture.

http://groups.msn.com/GamecatcherUploads/shoebox.msnw?action=ShowPhoto&PhotoID=6

For anyone whos seen this, could you tell me how to fix it? I've been to told its a problem with a text file, and I think I know which one, but I dont know what to modify.

Thanks.