I would guess from the screenshots that the requisites issue is caused by the section with the trees. It looks like it could be too wide and open. You have used solid "F" walls in your, right?
-Frogulis
EDIT: Just saw the very-very-very deep hole/well/plunge-pool in the ground inside the castle. Try removing that and see how it runs.
-Frogulis
EDIT: Just saw the very-very-very deep hole/well/plunge-pool in the ground inside the castle. Try removing that and see how it runs.