How to reproduce:
1) Open the attached project
2) Build and run on Android device
3) Upon app launch, deny camera permission
4) Click the button in the middle of the screen to start camera
Result: Crash

Reproducible: 5.5.0b11, 5.5.1p3, 5.6.0b7
Not reproducible: 5.4.4p2

DUT(reproducible):
LG G5 [LG-H850], Qualcomm Snapdragon 820, Adreno 530, OS 6.0.1
Motorola Moto G (4), Qualcomm Snapdragon 617, Adreno (TM) 405, OS 6.0.1
Samsung Galaxy S 5 Neo [SM-G903F], Samsung Exynos 7 Octa, ARM Mali-T720, OS 6.0.1

On earlier Android OS versions if not requesting authorization to use the webcam Application.RequestUserAuthorization(UserAuthorization.WebCam); Application also crashes, but this might be expected

DUT(not reproducible):
iPhone 6+ (iOS 10.1)