ProBoolean messing up my terrain

[Obelisklaser]

When i used to you 3dsmax8 this was never an issue it never did this to my terrain but in 2017(updated version) It does this to my terrain causing vertices to collapse randomly throughout my terrain when i make a simple subtraction to put a tunnel hole in my terrain. I've uploaded the before and after photos. The before is before i select operand and the after is after i have selected operand. 

Also when i try to use boolean it makes the object i have selected disappear?

Thanks for any help!

Also when i try

[Obelisklaser]

Good news i found a way to do it with boolean despite that it makes my object invisible so i'm not sure if probolean is supposed to do this? or i don't know