I expected to see 3 ladders for this crafting recipe, and get 12 ladders. What I got as no item at the end of the crafting bench.
This is on a 13w47c server as well.
I have the dev console in the back just in-case.
MC-40976
Item 'Ladder' Uncraftable
Resolved
Invalid
0
That is the incorrect recipe for ladder.
Try the correct recipe and try crafting it again.