This is what it says:

Any ideas what the matter is?
It's because those giant outdoor sectors. They're eating up tons of memory, and so you need to use the -mb parameter to feed more memory into Legacy.
so i type -mb into the box before I launch?
-mb and then a number. So for example: '-mb 128' (No quotes.)
For me, 128 got the game going, but the FPS was very, very low. I didn't test it with a higher number.
thanks xbolt...
I never knew you could do that...