data couldn't be read because it isn't in the right format

See if any of the info on this page helps: If you can't connect to the App Store, iTunes Store, or Apple Books - Apple Support

I just updated my system to Mojave, and now when I try to sign into the App store, this message pops up after I enter my ID/password correctly, and the correct verification. Why is this happening?

There was some resolve in this thread with the App Store—

https://discussions.apple.com/thread/8552064?answerId=33983064022#33983064022

Having t do with backup files interfering.

data couldn't be read because it isn't in the right format

I just updated my system to Mojave, and now when I try to sign into the App store, this message pops up after I enter my ID/password correctly, and the correct verification. Why is this happening?

The subject line seems to be different then the content of your question?

What do you need help with? If you can't connect to the App Store, iTunes Store, or ... - Apple Support

Sign in with your Apple ID - Apple Support

Sorry, but we would not be privy to anything Apple support personnel might be working on or not.

If the links posted do not help and/or no one else has any ideas, I'd suggest you do contact Apple support.

There is no Apple support here - these are user to user forums. You will need to contact Apple support by clicking on the contact support link in the upper right corner of this page.

I have just updated my system to Mojave and now when I try to sign into the App Store, this message appear : data couldn't be read because it isn't the right format.

what is the solution?

Been having the same problem since past 1 month, ever since I updated to Mojave. Cant download/update via App Store. Also when I go to Appstore->Account->View information it shows 'Cannot connect to App Store'. Can anyone under warranty please contact apple support and post solution here?

This just happened to me too after updating to Mojave!!! Please someone help. I can't download any apps in the app store.

I can log in and out of iTunes, but cannot log in to App store.

This is obviously related to the Mojave upgrade - is anyone from support looking into it?

Thanks for the response - I was hoping someone in the community may be aware of a solution or whether support were looking at it or not!?

Thanks for that - but didn’t help as I only had the one copy of that file! Maybe I need to do a backup and try it after that!?

🥴🤔

please solve this issue i can not download anythin from App Store. my software version is Mojave 10.14.3

Having someone else contact Apple support for your problem will not work as the calls are logged with a serial number and the person calling will need to have the same Mac, exact same apps, and the same problem which is highly unlikely.

You will need to contact Apple yourself.