Windows 10, NVIDIA GTX970
I wanted to use the bevel tool with Profile factor 1.0 and even number of segments (4 on the pic) to add some edges to support my geometry, but the bevel tool affects the outer geometry and creates such "pompoms" in the corners. It works only for the orthogonal corners (like regular cube have), but even a simple box shape is affected by these strange "pompoms" in the corners. I think the outer geometry should always keep unchanged when Bevel Profile is set to 1.0.
Exact steps for others to reproduce the error
Blend file with included simple box shape.