Hello,
if some flood lights are presented and the player want to create the multi block structure (In my case, I tried it with the casting multi block), I get a message "missing: -air x(x-amount, in my example 7)".

I think the light sources, that the flood lights create, block some spaces for the structure.

MC 1.12.2
IE: 0.12-82
IRR: 1.2.1
Forge: 1.12.2 - 14.23.4.2705