I’ve been trying to complete The Sacred and the Corrupt for a couple of days now and I’ve had no luck with any of the fixes online now. Basically what happens is I walk into the the cavern to get Light’s Vengeance, but one of a few things happens.
I’m having this same problem, sent a ticket and got an automated reply for now, hoping to get a more meaningful reply shortly. But, for the record, mine works more like this:
I enter the cave and try to approach the glowing hammer and get frozen as the Lich King approaches. He walks up, gives his speech, and (ONLY SOMETIMES) he smacks the hammer off to the side, then starts spawning undead (though some are like already spawning and I don’t think they’re supposed to), and the Vrykul spawns, climbing up out of the ground. Lich King says whatever then unfreezes me and wanders off and I’m left to make my way over to the hammer on the ground. I do this, easily 1-hitting the undead as I go, then activate the hammer. It flies up into the air real slow-like, finally reaches the Vrykul and smashes into him and he and all the undead die.
That’s it. That’s where it ends. If you try to run up to the glowing hammer - no longer surrounded by a beam of light, simply glowing bright yellow, nothing happens. You can jump on top of it, go in circles, whatever you want, nothing happens from there. From what I can tell, a new opponent is supposed to spawn here. For some reason that opponent is not spawning.
The thing is, I’ve had MULTIPLE other problems with this in the interim. Sometimes, other players are there, trying to activate the same thing, so the Vrykul and all the undead are already there, but the hammer over to the side that you can click and activate isn’t, instead, the hammer’s just laying on the ground right next to the Vrykul. Sometimes you walk in and there isn’t even another player there, the Vrykul is just spawned with all of the undead, and you STILL trigger the Lich King who freezes you, and he literally spawns a second Vrykul. When you activate the hammer in THAT case and he dies, the original Vrykul pops back up / is still there, and there’s still undead wandering around. And then nothing happens, you go near the hammer and it doesn’t trigger the boss spawn.
So yeah. There’s a big problem here, and I FEEL like it may be related to other players to an extent, but MOSTLY I think it’s related to the boss not spawning when you meet the requirements.
I am in the same position, and have lodged a ticket. Just awaiting a response.
There is a blue post about it The Sacred and the Corrupt - Support / Customer Support - World of Warcraft Forums (blizzard.com).
Also refer to https://us.battle.net/support/en/article/2529 which provides the link to submit the ticket.