Hearthstone patch pledges to fix several bugs — Instead introduces bug that botches game launches
An update to Hearthstone came out today alongside patch notes by Blizzard. The notes talk about certain balance changes and bug fixes but fail to talk about a bug the update actually introduced. Installing it means no longer being able to boot the game. Try to start the game and you'll see the error "'Unable to load mono library from 'C:/Hearthstone/Hearthstone_Data/Mono/mono.dll' (error = 126)." Wonderful!
Luckily, there is a quick fix to this. The lovely people at PCGamer found out that by clicking the "Scan and Repair" option after clicking "Options" located under the "Hearthstone: Heroes of Warcraft" logo on Battle.net, you should be free of this issue.
While many of us wonder how this could slip past Blizzard, it's only a matter of time before another update comes out fixing this. But for now, you can simply hit Scan and Repair.