Using VR in standalone mode will cause the screen to go black in 4.8

If a user launches in standalone mode with the oculus plugged in and turned on and then proceeds to press Alt+Enter then the screen will just turn black. Must have multiple tabs in the editor open to cause the black screen.

1. Open First person shooter project
2. Make sure that the oculus is plugged in and turned on
3. Play the project in Stand alone
4. Press Alt+Enter
5. Notice VR mode works as expected
6. Close the stand alone window
7. Play in Stand alone
8. Press Alt+Enter
9. Notice that the Stand alone screen goes black

Expected: VR Mode is enabled
Result: Black screen with sound

[4.8] VR isn't working anymore on Oculus DK2

No more Oculus Rift support for Mac in 4.8??

Project can only work under VR Preview mode

[4.8] VR isn't working anymore on Oculus DK2