Every time I try to use Surface Tracking SDK 3.0.1 on Android 5.0, 6.0 & 7.0, the camera won't work and keep showing invalid key with a black screen. And on SDK 2.0 still with black screen. I've used Unity 2019 and 2018 and still didn't work. I'm trying to make a SLAM app and couldn't find any specific tutorial about SLAM tracking with easyar. Please help.