Mac App Store Kerfuffle Prevents Purchased Apps from Running

This is one for the Department of WTF. I noticed on Twitter this morning that several people were having issues launching apps downloaded from Apple’s Mac App Store. I’m not seeing this on my iMac, but on my MacBook, most – though not all Mac App Store apps – display this alert when I try to launch them:

Mac app store wtf

There’s something going on with the way apps are validating with the Mac App Store. Apparently, the only solution is to delete the apps and re-download them from the Mac App Store. One at a time.

It’s not clear why this is only affecting one of my Macs, or whether this is a permanent issue with these apps, or just a temporary glitch that may resolve later today or tomorrow. Some people are reporting only getting a dialog to sign into their Mac App Store accounts. If you start work today and see a bunch of these dialogs, arm yourself with patience as you re-download a lot of your apps.

This is great for those who, like me, have very slow internet connections… Thanks Apple.

Oh, and this is yet another reason to buy apps directly from developers instead of from the Mac App Store.

Update: Oh, it turns out that Apple’s certificate has expired. Seriously, what a bunch of noobs sometimes…

Update 2: Michael Tsai has an excellent overview of the problem, the reactions, the solutions, and the blame game.