WoWCenter.pl
wikass zabił Mythrax the Unraveler (Normal Uldir) po raz 2.     
kuturin zdobył 7th Legionnaire's Cuffs.     
Nikandra spełnił kryterium Loot 200,000 gold osiągnięcia Got My Mind On My Money.     
Tooly zdobył Fairweather Helm.     
Muattin zdobył osiągnięcie The Dirty Five.     
Yoozku zdobył Parrotfeather Cloak.     
Mlody89 zdobył Royal Apothecary Drape.     
Weakness zabił Dazar, The First King (Mythic King's Rest) po raz 6.     
liq spełnił kryterium osiągnięcia Saving for a Rainy Day.     
Osiol spełnił kryterium osiągnięcia Saving for a Rainy Day.     
Wuntu zabił Zek'voz, Herald of N'zoth (Heroic Uldir) po raz 1.     
Olsa zabił Vectis (Heroic Uldir) po raz 6.     
Sarenus spełnił kryterium osiągnięcia Saving for a Rainy Day.     
kajtasus zdobył osiągnięcie Come Sail Away.     
ossir spełnił kryterium osiągnięcia Saving for a Rainy Day.     
mcpablo spełnił kryterium Alliance players slain. osiągnięcia Frontline Slayer.     
Emmm zabił Taloc (Heroic Uldir) po raz 17.     
AsaGorth spełnił kryterium Big-Mouth Clam osiągnięcia The Oceanographer.     

Outstanding Customer Service

blizz -> wysłany:
I made a ticket yesterday about how i killed Krosus on HC for the first time and couldn't open the chest or receive loot. The answer to my problem was quite baffling i'll post a screenshot of the answer from the Game Master so you can make what you want of it.

http://imgur.com/a/5Wohs

PS: This was not the answer what i was hoping for at all.
blizz -> wysłany:
Hey there Enhancement,

If you have any feedback about the Game Master that handled your ticket, then you can leave this directly in the survey that follows a contact. There is however no need to open multiple topics about the same issue, so I will be locking this duplicate thread down now.

That being said, the loot lock-outs are indeed split into difficulties, so having killed Krosus on Normal wouldn't have impacted your first kill on Heroic.
If you ran with Personal Loot, then any loot pieces you could not pick up from the chest directly would have ended up in your mailbox though. If you didn't see anything there, then the chest won't have contained much more than a few gold coins which is not something the Postmaster system would pick up however.

If you frequently have problems with looting chests, then make sure to retest things after a User Interface Reset.