The villagers

I have an invulnerable villager and it works. Remember that in a snapshot, invulnerable entities were made "vulnerable" against players in Creative mode. Change to survival and check.

Invulnerable tag for villagers does work.

/summon Villager ~ ~ ~ {Invulnerable:1}

Test on Survival or Adventure Mode

Invulnerable mobs are invulnerable to anything except for players in Creative mode, which is intended. (Otherwise how would you kill them?)

Is this still a concern in the current Minecraft version? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases. If this has been done, we can reopen the issue.

Keep in mind that the "Resolved"-Status on this ticket just means "Answered", and that we are waiting for further information on whether this issue still exists or not. We will reopen it as soon as the requested information has been delivered.

Ticket resolved as incomplete, because no answer in a reasonable amount of time (1+ year), if it still happens, please update the ticket.