No, it's just a plain simple map.
BTW I have made an edit to my previous post.
edit:
Meh forget what I said, the error is back. I am completely lost here. Just half an hour ago my map with two shadow casters didn't work, then a few minutes ago it DOES work. Now I remove the lights again and the map doesn't work (even though it did work before).
So much for work motivation.
edit:
Magically all versions of my map work again. Trolololo?
Is it possible maybe that background applications conflict with the engine? Maybe a firewall, virusscanner, modeling software?