"We offer new support options and therefor the forums are now in read-only mode! Please check out our Support Center for more information." - Vuforia Engine Team

Attempted to dereference garbage pointer

I'm getting a crash using Vuforia when I rapidly create a view using Vuforia and then tear it down.

I have a tab bar view controller and Vuforia is in one of those tab bars. Each time it becomes visible I create Vuforia and each time is disappears I tear it down to reduce my memory footprint. Occasionally I get a crash on an iPhone 4S that causes my app to crash. Its a 'EXC_BAD_ACCESS' crash which normally would not give me much but using KSCrash I have a backtrace. Apparently a notification from AVFoundation causes the crash, the exact diagnosis is 'Attempted to dereference garbage pointer'

Has anyone seen this kind of bug before? 

I've attached the crash report.

It is hard to diagnose from the crash report.

 

Each time it becomes visible I create Vuforia and each time is disappears I tear it down to reduce my memory footprint.