Steps to reproduce:

1) Download attached project and open in Unity
2) Build and Run 'TestScene' on a device
3) Wait around 1-2 minutes after permission request window will appear
Observe crash

Expected result: Application should not crash
Actual result: Application crashes after 1-2 minutes if permission request window for photos, media and files stays idle

Reproduced with:
5.5.4p1, 5.6.2f1, 2017.1.0f1, 2017.2.0a4

Devices under test:
Reproduced with:
Verizon SM G930V, OS:6.0.1, CPU:arm64-v8a, GPU:Adreno (TM) 530, Build:Verizon/heroqltevzw/heroqltevzw:6.0.1/MMB29M/G930VVRU2APG3:user/release-keys

Not reproduced with:
Samsung SM G903F, OS:6.0.1, CPU:armeabi-v7a, GPU:Mali-T720, Build:samsung/s5neoltexx/s5neolte:6.0.1/MMB29K/G903FXXU1BPF4:user/release-keys

Samsung SM G800F (Galaxy S5 Mini), OS:6.0.1, CPU:armeabi-v7a, GPU:Mali-400 MP, Build:samsung/kminiltexx/kminilte:5.1.1/LMY47X/G800FXXU1BPC4:user/release-keys

Samsung SM G935F, OS:7.0, CPU:arm64-v8a, GPU:Mali-T880, Build:samsung/hero2ltexx/hero2lte:6.0.1/MMB29K/G935FXXU1BPLB:user/release-keys

Resolution: Device specific issue. The device where this was reproducible has received an official update to Android 7.0 and the issue is not reproducible anymore.