I have the same problem!
I have unity 5.3.2 (both 64 and 32) bits, but I'm running my project on 32 bits. I selected IOS and Android when I was installing. I'm using Vuforia 5.0.10
I'm trying to run a very simple AR project just to test Vuforia and Unity. But I only gey this error
Cannot use web cam, since the user has not authorized this!
So please can you help me!! This is driving me crazy.