It opens in inkscape and browsers correctly. But when I open it in Carbide Create (289), not all of the boxes appear. Particularly, the piece that has overlapping rectangles only appears as one rectangle in CC. I’ve limited this next svg just to the shape with the issue:
Carbide Create seems to ignore / miss overlapping paths — this may be intentional — I was able to bring in those paths by insetting them by a point — just lie to the app about the endmill diameter.
Please send the file to support@carbide3d.com and a developer can respond to whether this is the intent or no. If it is intentional, we’ll add it to the list of known limitations.