Blizzard has temporarily disabled the opening of Hearthstone Standard and class packs while it investigates a "potential issue" with them. The nature of the issue hasn't been specified, but from the looks of social media it seems very much like the new, and supposedly ultra-rare Signature cards that went live today could be at the root of the problem.
It's not the cards themselves that are the issue, actually, but the fact that they seem to be appearing far more often than they should. Signature cards can be had through Standard, Class, and March of the Lich King card packs—March of the Lich King (opens in new tab) being the new expansion that went live today—but they're meant to be exceedingly rare, with a drop rate from Standard and Class packs equal to that of Golden Legendary cards. According to Hearthstone Top Decks (opens in new tab), that means players will see, on average, one Signature card appear for every 181 packs opened.
But for some players, that's not how it worked out. Instead, they got this:
Note that the Signature cards are the monochromatic ones with the fancy themes. (The idea is that they're themed around each expansion, so in this case an icy hue—although that hasn't stopped the community complaining that they actually look more boring than normal legendaries, but we digress.) Anyway, either this player got luckier than god, or… Oh no, here comes more:
I'm not a Hearthstone player, but I'm pretty sure that's not right. Getting one card like this is an incredibly rare event; pulling two from the same pack is unheard of. More than two? That's just busted.
Not long after the new cards went live, players began noticing that they couldn't open Standard or Class packs (opens in new tab) anymore, leading to numerous complaints on the Hearthstone forums and subreddit. The initial assumption was that a bug was keeping packs from opening, but Blizzard eventually confirmed that it had locked them down intentionally: "We are temporarily disabling pack openings for Standard Packs and Class Packs while we investigate a potential issue with those packs," it wrote in a "known issues (opens in new tab)" forum post.
Blizzard said in a statement sent to PC Gamer that there is currently no estimate as to when Standard and Class card packs will be re-enabled: "While we don’t have a timeline for a fix yet, our team is actively working on the issue and committed to provide a solution as soon as possible."