You need more Torch Men, more torches!
Notice that you have only 3 Torch Man, but Iron Miner consumes -1 torch each.
You have too little Torch Man's (Iron Miner's don't have torches so they cannot work).
But I understand why it looks weird, it is not clear what resource is missing unless you really think about it. I'm trying to think of a good way to make this more clear.
Thanks for the feedback!