Baked AO Unity 5

Hi! We are moving from Unity4 to Unity5 and I'm trying to bake AO to make the picture look that way it was with Beast.
Unity 4 screenshot:

So I need that smooth AO effect under plants and other stuff.. But after days of experiments all I got is that strange artifacts:

Can someone tell me why AO is baked so weird even without any lights (only ambient)?

One more day of experiments and I figured out that Default Parameters > Edit > Backface Tolerance set to 0 makes my baked AO much better.

It's not so good as it was in Unity 4, but I think it's enough for now.


Where is " Default Parameters > Edit > Backface Tolerance "?

I'm having the same problem.