[Emperor's Child]

It sounds to me like you are running out of memory... I've an older computer with only 128meg ram, and have seen similar issues with some of my games. Sometimes my game turns won't load with a similar type of strange out of range message IIRC. If you don't have a computer with gobs of RAM and started out the game with no problems, the game turn files have probably become large enough that they are giving the computer problems.