Incredible generosity: in Heardtone, players began to drop very rare cards several at a time. Blizzard is already working on a fix
Blizzard has temporarily disabled the ability to open Heardstone Standard packs and classes, as a bug has been discovered in them. It is not known what exactly the bug is, but rumor has it that it is all about the new and allegedly super rare Signature cards that started to be used today.
In fact, the problem is not in the cards themselves, as many might think, but in the fact that they fall out much more often than they should. Signature cards can be purchased in standard and class card sets, as well as March of the Lich King, a new expansion that was released today. The sets in it are equal in rarity to the frequency of Golden Legendary cards. According to Heardstone Top Desk calculations, this means that you will get one card per 181 open packs on average.
At least that's how it should be, but today players saw it:
Shortly after this bounty, players began to notice that they could no longer open Standard or Class packs, leading to numerous complaints on the Hearthstone forums and subreddit. A little later, Blizzard published an official statement on the matter: "We are temporarily disabling package opening for standard and class packages while we investigate a potential issue with these packages."
It is not yet known when the ability to open packs with cards will become available again.
Source: PC Gamer