Steps to reproduce:
1. Open QA stripped project
2. Deploy to device
3. Press 'Switch Direct' button
-- CRASH

Reproduced on: 2018.2.0a1, 2018.2.0f2, 2018.3.0a6
Not reproduced on: 2018.1.0b1, 2018.1.0f1, 2018.1.9f1

DUT:
Reproduced on:
VLNQA00012, Samsung Galaxy S6 (SM-G920F), Android 7.0, CPU: Exynos 7 Octa 7420, GPU: Mali-T760
VLNQA00121, Samsung Galaxy S9 (SM-G960F), Android 8.0.0, CPU: Exynos 9 Series 9810, GPU: Mali-G72
VLNQA00018, Google Pixel (Pixel), Android 8.1.0, CPU: Snapdragon 821 MSM8996 Pro, GPU: Adreno (TM) 530
VLNQA00147, Razer Razer Phone (Phone), Android 7.1.1, CPU: Snapdragon 835 MSM8998, GPU: Adreno (TM) 540

Workaround: Stop WebCamTexture and wait for a frame (wct.Stop(); yield return null;)

Fixed in: 2018.2.13f1, 2018.3.0a7 and newer.