Hi Andre,
<< What are "Invalid Normal Arrays"? >>
It's a state of adulterated executable instability.
<< How can they be avoided? >>
Remove any virus' or other forces that modify executables on your machine.
<< If they are formed how can they corrected? >>
Remove the tendencies and reinstall 3DS from the original shipping floppies. If
your problem persists, contact your dealer for a set of replacement discs.
jonas[adesk]