Underground Structure doesn't generate any air blocks?

I'm trying to make an underground structure, and it seems to be working perfectly besides the fact that it doesn't generate any air blocks. I'm using the bury terrain adaptation, but I've tried using none as well and it doesn't work. I generated a few of the structure files using structure blocks underground, and it generated air blocks, and the structure void I had put in them worked as well. I really have no idea what's going on. You can see the buried structure in the screenshot, or at least the non-full blocks.