After editing poly (removing edge) Boolean doesnt work

[Anonymous]

Hi! I'm quite new here, so it can turn out there is a simple answer to this - but I got to ask.

In order to avoid long narrow polygons that would flicker etc, I have divided my box in 3 segments in length, width and height. I have converted the box to Editable Poly, and have applied already several Boolean operations to the box. 

Cutting windows using Boolean - Subtract, of course one of the windows happened to be just on an edge which is created by one of the segments of the box. It broke the model, so I went into Editable Poly under Boolean in the modifiers stack and removed this edge with Ctrl+Backspace. After that, when I try to apply Boolean in order to cut the windows again, it doesnt work any more. 

Is it so that since Editable Poly is under Boolean in modifiers stack, going under the Boolean and editing the poly means I have ruined the whole thing and need to remove Boolean and redo all the Boolean operations already applied on the Box? Are there any solutions to this problem such as: how to avoid redoing all previous Boolean operations, or potentially also how to more effectively avoid the long narrow faces (if I dont divide the box into segments and get the narrow faces, I could add additional edges later on using Cut? But even if so, I again end up working with Editable poly under Boolean which will again ruin my Booleans?)

Any help much appreciated!

[Anonymous]

File examples would help.

[RobH2]

Sounds like it's not 'manifold' anymore, meaning it's not watertight or completely closed. So turn it back into an 'Editible Poly' and go to 'vertex' sub-object and select all of the vertices. Then 'weld' with a small setting, like '.001' or something. See if the vertex count gets smaller. Now try to boolean again. 

You could also add the modifier 'STL Check' and turn it on to see if there are any issues. It will expose a host of problems. Fix them and then try again. 

[Anonymous]

Boolean (the new one) should work with non watertight or non manifold objects, at least in Max 2018.

But pro booleans (the old one) will crash Max with non manifold objects 

[Anonymous]

Thanks for the replies! I didnt know this about watertight and proBoolean vs Boolean.

Actually, in my case it turned out that going to the previous file version with initial Boolean operation applied, right-clicking the object and converting it into Editable Poly (another option would be right-clicking Modifier stack and choosing Collapse All but that wasnt available) before continuing the editing and applying additional Boolean did the trick! ..