No Plugins Window. (OS X)

I installed UE 4.9 on my mac. I am attempting to get it to work with the Oculus Rift. I noticed that there was no option to output to Oculus Headset, and the “VR Preview” option is grey. (In the Play pulldown menu). Further research informed me that I have to enable plugins in order to get this to work. To enable them, I was instructed to go to the Plugins window under the Window menu.

There is no Plugins window listed in the Window menu.

I decided to go to UE4 preferences, and found at the bottom of the prefs, ‘Plugins’. Only one thing is listed, “Graphics Switching”. There are no other plugins, and the ‘add plugin’ button is disabled.

What in the world is going on here? I cannot add plugins apparently, and there’s no standard window with which to work with them anyhow.