I was playing Minecraft when one of my favorite worlds got corrupted. I tried to fix it but in the end I had to delete the worlds (which sucked). I made a new world and found a village and in it there were no farmers. All of the farmers were replaced with green villagers. I rebooted Minecraft (the entire thing) and they are still there. Not only that but when you punch a villager they don't make an "angry cloud" above their head.
This isn't a bug but a feature in 1.11. As shown on this wiki page villager have one of many professions. One of these is the Nitwit. They have no trades, and this is also likely why no 'angry cloud' appears when they are attacked (this is part of the popularity system and I would guess that Nitwits do not follow this system).
I believe that as of 1.11 it is also possible (though rare) to find a village comprised of nothing but this villager profession, which is what you have found here.
TL:DR There is nothing to fix here. Keep exploring and hopefully the next village you come around will contain villagers of other professions.