Boolean difference resulting in fatal error

[micheus]

Crawdad, that is one of those minimal situation not covered by boolean.

Your topology is broken and that causes Wings3D to fail in this "simple" operation.
The region where you getting the problem has two internal and strange faces, meaning something went wrong in your process to build that part of the block.



I fixed your model and then you will be able to get it right now ...


... as you can see bellow. I attached back your project so you can do the boolean by ourself.



You told us you used mirror and then got those "parallel" faces. That happens because mirror will copy and bridge the selected face. Take a look in this tutorial (starting exact in mirror) where I used mirror a couple of times in sequence and notice what I do when I want to mirror the entire half of the object I just created - I remove one edge to make that an entire face.


p.s. Please, report possible bugs in the Bug Reports session.