Game won't run in VR on oculus rift.

When I launch the game from within oculus home, the game starts to display in the oculus. I can see the Minecraft Windows 10 Ed Beta logo in VR, and below it, I see

Checking for updates (this stays for a few seconds) then

Launching...

then I get the message

"Failed to launch Minecraft"

Press (A) to exit.

When I press A on the controller, I get dropped back into oculus home.

Also I should add that video drivers etc are the most recent (368.81 at the time of writing this) and minecraft runs fine from the ms app store (on my monitor) and has the correct version number (0.15.6)

I have Trend Micro antivirus and Malwarebytes installed. This minecraft problem occurs even if my anti-virus etc is completely disabled.

If it helps, some more info: Both of the monitors I use, and the oculus are all plugged into the same video card. I typically have SLI enabled, but there are no display devices physically plugged into the 2nd GTX980. I have no problems running other rift titles with this setup (elite dangerous, Eve: Valkyrie etc)

I tried disabling SLI (2xGTX980 Ti), and this also had no effect.

I'm happy to attach log files etc if you tell me what you need and how to get that information...