I haven't tried packaging Flex for IOS.
In the native IOS world, some IOS developers had problems with their native apps because of some changes in IOS, resulting in black screens.
I have seen the same black screen from released Flash-generated IOS apps. Two of my apps have black screens, two 'hang' on the loader image.
All these were produced with CS6 with Air up to 3.4. This version of Air is way behind the current version now offerred with Flash CC.
I'm thinking we both have problems because we are packaging with an ancient version of Air.
I haven tried re-packaging yet.
That sounds like it may be the problem. I have downloaded AIR SDK 15.0 and installed it according to Adobe instructions. I edited the xxx-app.xml file to <application xmlns="http://ns.adobe.com/air/application/15.0">. I now get an error when compiling that says that this is a Invalid Namespace. I've seen a few posts that talk about updating the PATH in setupSDK.bat but I can not find this file.
This did solve my problem. Thank you! A new version of FLEX and AIR needs to be installed using the Apache Flex SDK installer. Download and run the latest version of this installer.
Glad it worked out!