This is a screenshot from xcode after a crash, the vuforia scene is the unique scene in the project.

Hello, we have the same problem here with Vuforia 6, Unity 5.3, xCode 7.3 and no custom shaders.

Through my work with vuforia, I have noticed that certain custom shaders are not compatible with metal, and will cause a hard crash like the one you are referring to.  I'll be diving into this problem myself tomorrow.

i try vuforia sample and all works correctly. i don't know why

Have you tried the Vuforia Samples first ? do they work correctly ?

Would it help if I sent you the project file?

I've gone through the following set of tests this morning:

• Vuforia 5.5.9 - Image Targets sample app + Unity 5.3.4f1, tested on iPhone 5S with iOS 9.2.1, using latest Xcode 7.3.1
• Vuforia 5.5.9 - Image Targets sample app + Unity 5.3.4p6, tested on iPhone 5S with iOS 9.2.1, using latest Xcode 7.3.1
• Vuforia 5.5.9 - Image Targets sample app + Unity 5.3.4p6, tested on iPhone 5S with iOS 9.3.1, using latest Xcode 7.3.1
• Vuforia 5.5.9 - Video Playback sample app + Unity 5.3.4p6, tested on iPhone 5S with iOS 9.3.1, using latest Xcode 7.3.1

In all cases I have used Automatic Graphics API (i.e. using METAL) and I got the App built and run successfully; I did not observe any issue, neither at build time nor at runtime.

Is this issue reproducible with any of the Vuforia Unity Samples ?

Not sure if this helps, but in the Player Settings, if Auto Graphics API is turned off, and Metal removed from the Graphics APIs list, it runs.

Clearly a problem with Metal.

+1....same problem here.  Unity 5.3.4f1 and Vuforia 5-5.9.

Can't run the app at all.

i have the same problem with unity 5.3.4f1 and vuforia 5.5.9