Steps to reproduce:
1. Open the attached project
2. Open the FirstVRtest scene
3. Switch platform to Windows Store
4. Play the scene (when Mixed Reality Portal is on and set up for developers use)
5. Pause the scene in Editor
6. Observe the assertion:
Assertion failed: Unable to get a camera pose while updating camera information

Actual results: Unity throws the assertion
Expected results: Unity should not throw assertion

Note:
Make sure you are running Windows 10 build 16257 or higher

Reproduced with: 2017.2.0b8, 2017.2.0b11, 2017.3.0a7
Not reproduced with: 2017.2.0b7
Regression introduced in: 2017.2.0b8