An unknown error has occurred app store

This solution is based on the idea, that for AppStore login the main network adapter name must be "en0". And really some people reported succes after rebuilding the interface list.

For me this did not work. Like other solutions circulating in the internet. As system programmer I do not believe that AppStore application has data link layer dependecies, but its worth a try.

Yet if I can use the App Store from another user account, that suggests there has to be something lurking in my main account's Library (probably) that's causing the problem...

And that's the problem. I've been on the phone for hours, deleting this file, and that one. Anything possibly related to the App Store went into the trash - dozens of restarts, booting into "safe mode", etc. And nothing fixed the problem. Yes, we deleted network preferences as well, tried to log in via ethernet as well as Airport Wi-Fi.

So, for now, any time I see that I have an update, I'll log into my "test" account - the one that's a stock Apple install - and update.

I agree it's strange though I'm thinking we have an uncaught exception that's tossed all the way to the top level which is "unknown error" and that means we could easily have multiple issues covered here

Supporting: The various fixes posted are certainly working for some, while none of them have been effective for myself and others. This suggests it's possibly different core issues that all manifest with "unknown error".

The trick of adding Ethernet (en0) and set it as second network adapter is system preferences did the trick i am now able to login in the apple appstore and upgrade to osx mavericks i have the rtl8111/8112 onboard lan kext that fixed the onboard lan card. search for youre mainboard brand for the model of youre onboard lan card and search for the kext if the driver is not avilable in the system network preferences

All of a sudden, working for me as well (Late 2009 iMac, Mountain Lion 10.8.2). As I was told when I called about the original issue, "there's a problem at our end." Guess they fixed it. 😉

Just got this error tonight....did a google search found this thread and this post worked for me.

Thanks

Repair Disk Permissions is what fixed it for me. Good luck!

The T&C trick worked for me too.

I tried some of the proposed solutions but only the T&C trick did the job! 😉

Thanks to Mohd.....

When you DELETE the plist file YOU HAVE TO RESTART YOUR COMPUTER!!!!!

If you don't reboot your computer there will be no change.

It finally works for me thank you Mohd!!

Just sign out then sign in with your other account but not when its asking you your apple id to download an app.

I've tried all of this now, logging in with different accounts, but nope! Still that "unknown error." I could contact Apple support but I would have to make a long distance call, do they have any email?!

I have the same problem. It is something that has happened recently and nothing has changed for my system. I just now went into iTunes and viewed my account using the same ID. That worked fine. Must be just an app store problem.

I am also having this problem...but only on one of four macs. My family has two iMacs and two MacBook Airs. The problem only appears to be on one of the iMacs. I have just contacted Apple Support by e-mail and "Albert" is pleased to be helping me....I'll post if we get resolution.

I can't log in to App Store either. My TuneUp app keeps saying it was downloaded from another computer and needs me to sign in to download from the App Store. It was downloaded on this machine. It's the only one I have at the moment. I rebooted the machine, changed password twice, but nothing works. I keep getting "An unknown error has occurred" message. This has been happening for the past couple of days.

I'm having the same issue on an iMac with 10.7.4. Mac Mini, iPad and iPhone all work fine with App Store. Spoke with tech support. They suggested reloading OS. I did, but only change was that Safari kept crashing. Reloaded Time Machine backup to get browser working again. Very frustrating!