3D UI Buttons with VR Error

I have an experience with several 3D UI Buttons that trigger some animations via Storytelling. They work completely fine, unless I add a Vive Environment. Upon playing the experience I get the following error message and the buttons don't seem to work with the Vive Controllers or on the screen. Does anyone know what the 'density' is, where I can change it, and why it only seems to make problems with the headset in the experience?
Thanks!