Raising ocean level in world editor results in cars not moving

Basically like the title says. In East Coast: I pause, hit F11, raise the ocean level beyond the 8 or so it's defaulted to. The water rises up fine. Then I hit F11, unpause, and the car will no longer move. The wheels don't turn left or right. The engine doesn't rev. Nothing. I've tried restarting and nothing works. The camera can move with the controller knob but ever other feature doesn't work.

Can anyone who has successfully raised the water level tell me what I'm missing?

And, yes, this is with the car still on dry land

Thanks!

 

Enable drive in editor in the toolbar of world editor in top left of the screen. There's a picture of a car on that button.
And if it already is enable, disable that and then enable that again.

 

You're a genius, thank you!