ChamberLock very mad, no likey

[dsagfa]

I'm trying to place a ChamberLock in my test, but it keeps nagging me about some voxels it wants filled above, below, to the left and right of it, but when I fill it, it's still mad. How do I fix this? Am I doing something horribly wrong?

[TeamSpen210]

It also requires an open space on the other side of the wall, for the door to lead to. I should add guide images to show how it should be placed.