Can't complete the Molten Vault quest

I cleared everything in the Vault, killed Uz-whats his name, no Hammer dropped. Thought maybe I missed something. Reset fron the Portal, did it all again and still no Hammer. Did I miss something else? I've done this quest before on 2 other characters with no problems.

I am in the same situation with a character, any idea on how to solve the problem?

same here too, cleared it 3 times and killed the boss all 3 times, no hammer dropped. all my past other characters never experienced this though

Have the same problem with my new character. on my first character it works fine.