Crashing app

I want to find out the distance from my node to the point of terrain intersection.
I use the rayIntersects method and the returned intersection point.
But when I try to get the distance, either through the distance or normalise method of Vector3 my app crashes.
What could be wrong?
(I use ETM 2.2.)

How we should know your problem with so little information?, at least paste some code...

Oops, sorry my mistake... I used the wrong TerrainInfo instance (that was not pointing right).

I'm really sorry for taken up the time of the readers of this.