Vuforia failing to initialize AR/VR cameras on some Android devices

I'm having an issue with an app I'm building which is releasing very soon and need some urgent support. After extensive debugging, details to follow, I've identified that the AR/VR sample that Vuforia provides doesn't actually work on some Android devices, specific list of devices to follow, due to Vuforia failing to initialize. What makes this issue even trickier is in the same app some basic AR scenes work just fine and its only scenes that utilize the AR to VR transition as found in the ARVRSample project where Vuforia is failing to initialize.

Using LogCat I found this specific crash relating to my issue.

I/Unity   (30286): (Filename: ./artifacts/generated/common/runtime/UnityEngineDebugBindings.gen.cpp Line: 37)I/Unity   (30286):E/Unity   (30286): Could not initialize the tracker.E/Unity   (30286): UnityEngine.DebugLogHandler:Internal_Log(LogType, String, Object)E/Unity   (30286): UnityEngine.DebugLogHandler:LogFormat(LogType, Object, String, Object[])E/Unity   (30286): UnityEngine.Logger:Log(LogType, Object)E/Unity   (30286): UnityEngine.Debug:LogError(Object)E/Unity   (30286): Vuforia.TrackerManagerImpl:InitTracker()E/Unity   (30286): Vuforia.DeviceTrackerAbstractBehaviour:InitDeviceTracker()E/Unity   (30286): Vuforia.DeviceTrackerAbstractBehaviour:OnVuforiaInitialized()E/Unity   (30286): Vuforia.VuforiaAbstractBehaviour:Start()E/Unity   (30286): E/Unity   (30286): (Filename: ./artifacts/generated/common/runtime/UnityEngineDebugBindings.gen.cpp Line: 37)E/Unity   (30286):I/Unity   (30286): NullReferenceException: Object reference not set to an instance of an objectI/Unity   (30286):   at Vuforia.DeviceTrackerAbstractBehaviour.ApplySettings () [0x00000] in <filename unknown>:0I/Unity   (30286):   at Vuforia.DeviceTrackerAbstractBehaviour.OnVuforiaInitialized () [0x00000] in <filename unknown>:0I/Unity   (30286):   at (wrapper delegate-invoke) System.Action:invoke_void__this__ ()I/Unity   (30286):   at (wrapper delegate-invoke) System.Action:invoke_void__this__ ()I/Unity   (30286):   at (wrapper delegate-invoke) System.Action:invoke_void__this__ ()I/Unity   (30286):   at (wrapper delegate-invoke) System.Action:invoke_void__this__ ()I/Unity   (30286):   at Vuforia.VuforiaAbstractBehaviour.Start () [0x00000] in <filename unknown>:0I/Unity   (30286): I/Unity   (30286): (Filename:  Line: -1)

I'm using Mac Unity 64 bit 5.3.4f1 with Vuforia 5.5.9 publishing via Android Studio which based on my extensive research seems to be the preferred combination of development tools and SDK for creating this type of app.

I've currently gone through and tried almost every trick and tip from the forums relating to Android issues, non-Android specific issues where Vuforia is crashing, and then a bunch of forum posts and potential fixes relating to Vuforia failing to initialize. I've tested the app being published directly from Unity as well as from Android Studio with no difference. I've tried both types of license keys to see if that makes a difference and it does not. Also, the entire app works fine on iOS so it is clearly something Android specific.

Our QA team has seen the same crashing issue on the following devices:

• Samsung Galaxy S4 (4.2)
• Samsung Galaxy Note II (4.1)
• Cubot Rainbow (6.0)
• Acer Liquid Z220 (5.0)
• Samsung Galaxy Tab2 (4.5)
• Kobo Arc HD Android Tab (5.1)
• uHappy UP580 (5.1)
• Motorola Nexus 6 (6.0)
• Lenovo TAB 2

Additionally I would note that the app does perform as expected on my Samung Galaxy S6 which to me makes this entire problem even stranger.

Our project is almost complete and if I can't get this fixed in the next 2-3 days it will impact our release date.