4.15.0, SteamVR and Linux/Ubuntu? "VR Preview" greyed out

When I try to load the VirtualRealityBP MotionControllerMap, The “VR Preview” button is greyed out – I can’t test the scene on my HTC Vive.

VR Preview is also greyed out when I try to run using Unreal’s official set-up guide (https://docs.unrealengine.com/latest/INT/Platforms/SteamVR/QuickStart/2/index.html)

Any thoughts on how to fix this?

Running Unreal 4.15.0 on Ubuntu 16.10, Nvidia 375.27.10 (Vulkan build) proprietary drivers, SteamVR beta and Steam client beta for Linux, Unity 7.5.0 desktop environment, Xorg 1.18.4.

I added a post in the Steam forums, too (Unreal 4.15.0 "VR Preview" and VR Mode won't work -- greyed out. :: SteamVR Linux).

Update, this problem still seems to persist in Unreal Engine 4.16. Here’s a screenshot:

The “VR Preview” button is still greyed out. Tested in Ubuntu (GNOME) 17.04 x64, Unreal Engine 4.16.0 Linux build, Nvidia 381.22 proprietary drivers, HTC Vive, SteamVR latest beta build and Steam beta client.

Any thoughts on how to fix this to get VR preview mode working?

The latest SteamVR Beta 05/25/2017 broke UE4 compatibility, also includes packaged builds.

@mordentral, thanks for the info’, definitely appreciate it! Is stable branch broken, too? (Or did stable SteamVR branch ever work to begin with?)

Stable works, you can turn off SteamVR Home to get it working with UE4 again. Its something to do with the new Home update after the first one.