Unity terrain becomes semitransparent in build

Hello there,
I'm making a simple VR scene in Unity, and I'm currently stuck with a super weird graphics problem (which looks not to be VR related, because it happens even with a standard camera).

I'm using the Unity terrain with a speedtree tree model, grass, some rocks. Nothing fancy, pretty basic stuff.
While working inside the editor, everything looks super cool:



The problems come when I build the game. The terrain looks as if it was transparent or something, and I cannot figure out why. This is what I get. Look at the roots creeping out the tree on the right side, or the rock on the left side. It's weird.



Do you have any advice about what it can be and how to solve it?

 

Could it be something related to the global illuminations settings? Do the GI play well with the unity terrain?

 

This was a bug from standard terrain shader, especially when u use them with trees. Switch to legacy diffuse or better yet upgrade your unity. Because I think I have read that it is solved.

 

Well, I've got the latest Unity version. That's strange!

 

I had the same problem not long ago, and my "fix" was to export the project (or all the strictly needed pieces of the project anyway) and reimport it into a new, clean project. No idea what was ultimately causing the issue though.

 

At last, it seems to be solved just by unchecking the HDR checkbox on the camera.