3ds max 2017
There are certain situations in 3ds max where using a ProBoolean operation on a model will perform the geometrical operation but produce shading/smoothing artifacts, or problems in later operations like Chamfer.
* This can often happen with geometry (models) imported from other software like Sketchup for instance
In many of these cases setting the ‘Planar Edge Removal’ to ‘No Edge Removal’ in the ProBoolean Advanced Options will solve the problem.
The reason I’m not adding some visual example of the problem I described is that I couldn’t reproduce it..
So the tip is, if you perform a ProBoolean operation, and weird stuff happens,
Try setting No Edge Removal, it may solve the problem.