DesignType mod question

[Jmenschenfresser]

Heya.
I am trying to mod in extra design types for a race. I've added three attack ships to the designCreation.txt (Attack ships-heavy -medium and -light).

I've added them to the Construction_Vehicles.txt file as well so as they will be built.

And I have added the new types to the defaultDesignTypes.

However when firing up a game, i still get error Messages saying it cannot find the three types, and another error from the Construction_Vehicles.txt in not recognizing the new types to build.

Any help, please? Am I missing something, or can this be done. Everything seems to be spelled right. At a loss.

Many thanks