When you build a prison with 1 iron door,The Blueprint says you build 2 iron doors.Then i try to figure out what is the problem so i try to place 2 iron doors and match with the Blueprint.Blueprint says i placed 4 iron doors.It's a bug Blueprint count 1 iron door for 2 iron doors so build a prison is impossible.Sorry my english is not very well :D

its 1.20.1 version btw.

Probably a change in 1.20, since doors are technically two blocks. Its not gamebreaking tho, after all you need at least 1 door.

What is the issue is that your prison is a bit too small, 64 is the minimum here.

I will rework that, its quite a user unfriendly thing.

thank you.