Hi, since unity 3.6.5p3 (and p4) we have a huge problem with Vuforia.
It is really difficult to explain but I'll do my best.
Using unity 4.6.5p4, Vuforia 4.2.3 and Xcode 6.3.2. I export the App using IL2CPP Universal, I publish the App and build directly on my devices, all works good.
If I export the app for TestFlight or HockeyApp, it works fine on 64 bits devices (iPhone 6 and 6+) but it crashes on 32 bits devices (iPad2,3 etc).
Its crashing exactly on the scene that contains the ARCamera, I tried to disable the camera from Settings/Privacy/Appname and the app works, obviosuly without the AR.
This clearly shows that something in Vuforia is causing the crash.
I tried to download the App from Testflight and Using Xcode "Run Without Building" but doing this makes the app work fine. Basically I cannot create a crash report for this.
Unfortunately this thing happened on one of our apps published on the AppStore (we received many complains about the crash), thank God Apple granted Us an expedited review and we managed to send another update using Unity 4.6.5p2.
Unfortunately the latest version of Unity contains an important fix that we absolutely need, but I cannot send it to Apple until this problem is solved.