Simply doesn’t work 1/2 the time, if not more. What to do?
Booleans?
I usually try ProBoolean if Boolean does not work… 
I don’t use boolean !
I try that, too. I had to slice this one up.
I think what you did in the video is subtract both objects so you ended up with nothing. It’s a bit counter intuitive in the new Boolean system, but you shouldn’t change an object’s operation until after you have added it. Notice in the video both objects are set to subtract, while the one you are subtracting from should really be set to union.
There are some other weirdness to it as well I’ve noticed. When you add an operand the original object doesn’t get removed, but is just hidden and instanced into the boolean. That way you are effectively doing a nondestructive operation. Great, right? Well except it doesn’t do that for the original object you applied the boolean operation to. That object gets irreversibly changed into a compound object, since the new boolean system doesn’t allow you to extract booleans, only remove them.
So, the proper workflow is to take your first object, instance it (or copy if you prefer) and then apply the boolean. Next, without changing the mode, select the operand you wish to subtract. Now both objects should be unioned together. Now select subtract, and the second object should be subtracted from the first. If you do end up subtracting both, you can just go back to the first object in the boolean list and set it to union too.
Edit: Okay I went back and checked, and for me it does work even with all operands set to subtract. The only other reason I can think of for it not working is if the objects aren’t “watertight”. Fastest way to check is to apply the STL check modifier, or enter X-View with open edges.
I think Shimakaze is likely correct, perhaps an unwelded vert or overlapping faces or something which lead to non-water tightness. I’d be happy to take a look if you’d like Bobby and tell you for sure.
I exported the steps and imported them, but that didn’t help. I’ll did deeper tomorrow. It happens often.
start using Fusion 360 like I did 
For architecture?
coming from a maya background, where booleans have never worked Sometimes I would get the disappearing result, and scaling the objects up by 10 or 100 would fix it. Probably isn’t this but seeing as its Autodesk 
Use AutoCAD Seriously though, AutoCAD is waaay better for this sort of stuff. Sadly it costs about a million pounds. Booleans in Max have always been a bit hit-and-miss. You’d think by now they would have this sort of thing sorted properly.
for boolean stuff you need in your scene.
I find that Booleans usually fail because there are either holes, overlaps or tangled/coincident faces in your model. Though sometimes it will work fine on such objects and make you pull your hair out and say “But it was working fine five minutes ago! I barely changed anything!!”