This was from skirmish mode, testing the new city map - All I did was start the mission, didn't move any units, just swung the camera around to look at parts of the map, and when going to the top level where the alien ship is it crashed.
I'm not sure if this is something I did when building the installer/compiling the map, or if it is just because the city map is still a work in progress...
When the installer is done uploading, others can try for themselves.
Sorry if this was already discussed in a recent post, I've been busy the last few days and haven't checked into the forum as often.