Hololens fails to exitVR successfully

Description:

Given I am using a Hololens in immersive mode,
When I leave the immersive mode,
Then the aframe stops rendering (the browser window only display a white background and not the scene).

The reason the rendering is stops is due to an error being thrown within a component's tick. I haven't been able to track down the component. This happens with a blank scene.

The error is as follows;

TypeError: Unable to get property 'pressed' of undefined or null reference at tick (eval code:65:5) at tick.value (https://server/aframe/aframe-master.js:73647:11) at render.value (https:/server/aframe/aframe-master.js:73695:31) at bound (https:/server/aframe/aframe-master.js:77038:7) at animationLoop (https://server/aframe/aframe-master.js:27442:4)

As an aside, it would be great if component and system ticks were wrapped within a try catch. The catch could log the error via console.error and provide information of which component was being rendered rather than throwing and stopping the rendering.

• A-Frame Version: 0.8.2
• Platform / Device: Hololens
• Reproducible Code Snippet or URL: Any example

Reproduce the blank-scene failure on a HoloLens by entering and leaving immersive mode, then inspect the component or system tick shown in the aframe-master.js stack trace. The work is done when exiting immersive mode no longer stops rendering and the scene remains visible; the requested tick error logging is an additional consideration.