Vive/SteamVR can't preview

I have SteamVR running and my Vive works with other things. But I can’t use VR preview with it, I’m guessing because UE isn’t detecting it. I’ve made sure the SteamVR plugin is enabled, obviously, and as suggested in some places I’ve tried disabling the other HMD plugins, no effect. When I enable “simpleHMD”, I can use VR preview, but it only shows up on the monitor, not in the Vive.

Running windows 8.1, tried in 4.10 and 4.11.

I dont have a vive, but i know from testing yesterday that the vr preview isnt working vorrectly in 4.11 yet. Not sure why its not working for you in 4.10 tho