came across this while trying to ladder up a shaft i dug:
the mouse cursor is where i was aiming when placing a ladder. the ladder, as you can see, didn't appear on the side of the block i placed. found this out when i was trying to make a ladder up and the ladder kept being placed on the block behind me instead of in front, or sometimes refusing to be placed at all.
I had to dig away all the blocks in my shaft except the face i wanted ladders on for them to place properly.
tried different orientations and # of blocks surrounding the face and had issues with nearly all of them. (these are full blocks, not stairs or anything.)