@astaticmusic, How did you fix your issue? What did you determine was the problem? I have tried to Enable VR in multiple ways and my X-Plane 11 application still crashes each time.
(1) I have tried opening X-Plane without SteamVR running, and then starting SteamVR, and then Enabling VR: fail. (2) I have tried opening SteamVR, then starting X-Plane, and then Enabling VR: fail. (3) I have tried opening X-Plane and Enabling VR without SteamVR running: fail. (4) I have also rebooted to experience the same issue yet again.
My version is X-Plane 11.34