MC Version: 1.12.2
Forge version: 1.12.2-14.23.1.2560

When I try to craft the breakable wall parts I have what I believe is the correct setup: 4 projectors facing each other with a 3x3 open space in the middle. when placed, I see a orange overly of one block in the center.
I placed an iron block with redstone on top, and as far as I understand thats the correct layout, however, it gives me the error message: Invalid block Air (As seen below)

As far as the other recipes using the projectors, if I cheat in the wall blocks, then Im able to make the machines just fine. Its just this first one thats giving me trouble.

You can not craft a 1x2x1 recipe in a 1x1x1 area. There are currently no 1x1x1 recipes.
Increase your crafting area size and you are good to go.

And I'm a dork. Yup, Sorry about that. I feel silly..