Well, that was fun, in much the same way that banging my head on the desk is fun, which is to say not really, but that it’s nice when it stops. Assuming it has stopped, that is..
It started yesterday, when my iPhone popped up messages asking for my passwords to a couple of things I don’t actually use. It was a bit early, so I didn’t think much of it until later, when I tried to update some apps on my Macbook Air. That produced a rude message about my Apple ID, which suggested that my password has been entered incorrectly, and that I’d have to reset it. Well, I was pretty damn sure I’d done no such thing, but I went to the Apple site anyway and jumped through the necessary hoops to reset my security stuff. I then logged in to various things with no trouble at all.
But a short time ago, I tried to do similar updates on the iMac, and was greeted with a rude message about having entered my password incorrectly several times and that, yes, I’d have to reset it again. So I did. Mutter. Then I tried to log into the App Store again, and got the helpful “Unknown error” message. Hmmm. I checked, and my new password worked just fine in the iTunes store, so it had to be an App Store problem.
I did a bit of searching, and found this thread on the Apple support thingy:
This suggests deleting a plist file – this made some kind of sense, as if its settings were borked, this would account for the App Store playing silly buggers. I removed the file, restarted the App Store, and was able to log in. I had to confirm my payment details again, as that setting had been removed, but it’s now working properly.
My guess is that the settings had become scrambled on the iMac, which had tried to phone home for updates and offered a corrupted password, which locked me out of the account.
While I don’t actually recall this, I may have had a similar issue in the past – I had a renamed plist file in the Cookies folder dated from July last year.