The Group Boss in Nchuthnkarst Public Dungeon, Clockwork Criterion, has so little health that a group of 4 can kill it BEFORE it goes into its invulnerable phase and spawns adds. This prevents you from getting the Achievement and Skill Point for the Group Event.
I can only presume that you need to add a bit more health to it OR FORCE the invulnerable phase somehow. We got the Achievement & Skill Point on a second attempt where we did light attacks only until the adds spawned.
Guildmaster of the UESP Guild on the North American PC/Mac Server 2350+ CP & also found on the European PC/Mac Server 1700+ CP
These characters are on both servers:
Alix de Feu - Breton Templar Healer level 50
Brings-His-Own-Forest - Argonian Warden Healer level 50
Hrodulf Bearpaw - Nord Warden Bear Friend & identical twin of Bjornolfr level 50
Jadisa al-Belkarth - Redguard Arcanist Damage Dealer level 50
NA-only characters:
Martin Draconis - Imperial Sorceror Healer (Aldmeri Dominion) level 50
Arzhela Petit - Breton Dragonknight Healer (Daggerfall Covenant) level 50
Bjornolfr Steel-Shaper - Nord Dragonknight Crafter (Ebonheart Pact) level 50 EAGERLY AWAITING HIS BEAR
Verandis Bloodraven - Altmer Nightblade Healer & clone of Count Verandis Ravenwatch (Aldmeri Dominion) level 50
Gethin Oakrun - Bosmer Nightblade Thief (Ebonheart Pact) level 50