In Story Mode (and possibly elsewhere, no other event playing with Defenseless right now) the objective Defenseless always fails. It starts the game failed (0/0 in red) and it doesn’t matter if you play any creatures at all.
I would just like to second this, it’s exactly the same for me still today on July 29.
Also confirmed. I did a test of this yesterday on the Heroic Encounters, Heroic-Nissa fight #2.
No Defenders, all Defenders, no creatures at all, it didn’t make a difference as that objective was always failed.
Hi everyone, the team is aware that the Defensless objective is not functioning properly, and they are currently investigating the issue.
Tested it again today (v2.8) on the Heroic Nissa fight #2, and it is working properly, at least for this fight.
I was able to collect the Runes reward on this when using a creatureless deck.