Error delivering iOS App update. "This bundle is invalid. Apple is not currently accepting applications built with this version of the SDK."

Question

I reticently delivered an app to the iOS App store on 1/24/2014. It's an iO7/iPhone only app and everything was delivered correctly. As of yesterday my app was approved and it is currently visible in the App Store.

I put together a small update and am currently working on getting it delivered using Application Loader.

However, now when I upload my production IPA it gets rejected due to what seems like a sdk error.

Messages:
    Apple's web service operation was not successful
    Unable to authenticate the package: 806906410.itmsp
    ERROR ITMS-9000: "This bundle is invalid. Apple is not currently accepting applications built with this version of the SDK." at SoftwareAssets/SoftwareAsset (MZItmspSoftwareAssetPackage)

I'm struggling to figure out what has changed since I am building with the same SDK as I did last weekend.

Answer 1

From the February 1st you can use only XCode 5.X and iOS7 SDK to create apps for the AppStore. Double check that you compiled your app with the correct XCode/SDK.

Information about this: https://developer.apple.com/news/?id=12172013a

Answer 2

I was hoping your suggestion works but I got the error despite using Air 4.0 SDK. I didn't get this error when I uploaded it to the App Store a few days ago (I was already using Air 4.0 then). Does it really mean that Apple has limited development to using Xcode?

EDIT:

Updating to Air 4.0 SDK does work! But make sure what you have is Air 4.0 SDK for Flex Developers