To reproduce:
1. Open attached project;
2. Open "test" scene;
3. Enter play mode;
4. Exit play mode;
5. Repeat steps 3 and 4 until error "Assertion failed: VREyeTextureManager already had a texture." is thrown in the Console;
6. Exit Unity.

Expected result: no crash.
Actual result: Unity crashes on close when calling XRSettings.LoadDeviceByName with non-existent device name

Reproduced on versions: 5.5.4p1, 5.6.2f1, 2017.1.0b10, 2017.2.0b1.

Verified on: 2017.2.0b3 (4c2ac554540c).