The altarac ??? puzzles have been found. : r/hearthstone
Hearthstone: The Boomsday Project - Dr. Boom Lethal Puzzle Lab Solutions | Shacknews
Hearthstone Alterac Valley Secret "???" Achievement Guide - How To Get Shimmering Snowflake Card Back - Full Puzzles Solution - Hearthstone Top Decks
Hearthstone on Twitter: "As a temporary solution for players experiencing this issue, clicking "OK" through each error message will allow you to enter The Puzzle Lab or reinstalling Hearthstone." / Twitter
Hearthstone: Heroes of Warcraft 1000 Piece Puzzle – Blizzard Gear Store