I am running XPlane 11.26 in VR Mode (Oculus Rift).  I am running Windows 10 Professional (latest updates).  For some reason I no longer have any sound (engine noise, etc.) when flying XPlane.  I have deleted/renamed the Preferences file in the output folder but that has not made any difference.  I ran the XPlane 11 Update process and it stated that I am on the latest version of XPlane.  I verified, in settings, that all of the sound sliders are all the way to the right and that "Enable Sounds" is checked.  How can I get sound back in Xplane?