Hmm. I wondered because I'm fairly sure that it was something to do with distance fields that were causing crashes on our play-tester's computer as his is a 32 bit. I just yesterday actually got rid of the distance fields themselves in the name of optimization. It makes creating bodies of water more time consuming, but it is what it is.
Did the game crash at all? Or just fail to load?
I've also been experiencing random load failure, even when working in engine. It keeps outputting an infinite loop, but the crash logs don't actually point me to anything; just to an 'unknown function.' I've got some ideas as to what it could be, but I've yet to actually pin down the source.
Anyway, enough rambling from me. :p