The game crashed while I was moving some things out of my cube, and after restarting it the cube is just missing entirely and its contents were dumped into my inventory.
I even tried going to Halls of the Dead level 3 in A2 and opened the chest at the end, and there’s no cube. Now I’m worried about making any progress in case of a rollback.
If you are on battlenet, you should be able to either join a game with the quest open, or else make a game with a new character and try again.
Same issue happened to me just now.
yep just logged in and cube is missing.
Same here, logged and now cube is gone
This getting better and better every hour…
Just noticed mine disappear too, this just be an item that is on the base of every town like the portals
Just crashed as i was entering the portal to act 4. as i was clearing back down to Mephisto i went to sort my inventory and … cubes’s gone, soulstone dumped to inventory.
It’s nightmare so i’ll just push thru to the quest in hell but this is pretty annoying. I’ve crashed twice now after beating bosses but before using the portals and had to reclear down.
@rocdog just did that and the cube did drop from the chest in A2, so thanks for that. Kinda annoying though that we even have to do that. Oh well, all I lost as 1 perfect gem lol, so I guess it could’ve been worse.
Happened to me last night. This morning I just went back to the halls without quest available, same level and it dropped the cube again.
Missing the cube after server maintenance, went back to Normal Act2 and got it back from chest.
I just did the quest, got the cube, talk to Cain then cube disapeared.
Create a new game, re-kill Rada, no more cube…
I was able to go back to the hall of the dead 3 and kill the unique. Opened the chest and it was there.
Also lost all the gems i had cubed up to Pgems
I spent so much time and gathered 6 Perfect Gems and created a great Amulet.
When I re-enter the game, the cube plus my amulet disappeared!!
Blizzed! Give it back to me! My precious!
First and last time I will pre-order anything.
This buggy, glitchy mess of a “game” is the nail in the coffin for me.
I hope EVERYBODY sues the crap out of you, Blizzard!
Pathetic scammers and trash human beings that you are!
After a sudden power outage when I relogged into the game my horadric cube and some gems disappeared, now I can’t the cube back. 
If you happen to lose your cube as I did. you can load your character back into normal difficulty and fast travel to Act 2 Halls lvl 2. proceed to finish the tomb and it should Drop from the chest at the end (the chest illuminated by purple light.) it takes like 5 min.
I’ve only noticed some minor bugs like the Merc getting stuck. I don’t see what it is you’re experiencing.
Well this sucks.
Upgraded my viperskin using cube recipe. Aterwards I went to kill baal.
During the fight the game crashed. When I got back in my cube was gone and my viperskin too.
WTF