Ok, I down loaded a mod, that was made for me from my designes. It seems ok, but The names are wrong, and one of the characters crashes. The guy tells me, he has no problems, and think it is todo with my language set to Uk English.

How do I change what it is set to?

You can't change the language.

You'll need the source files and localize the units again.

Yep, the author only did localizations for U.S. English. It would take him all of five minutes to copy the U.S. localizations for all other languages.