Unity provides a great deal of support for UWP, including configuration of device capabilities. We need to enable a bunch of them for HoloLens as shown ahead:

1. If you have the Build Settings window open, press the Player Settings... button. Or, you can get there from Edit | Project Settings | Player.
2. Look across at the Inspector panel, which now contains the player settings.
3. Find the Publishing Settings group of parameters and click on the header bar (if it's not already opened) to find the Capabilities pane. Ensure all the following items are enabled (checked):
   • InternetClient - for Vuforia's cloud target database
   • PicturesLibrary - for PhotoCapture camera frame functionality
   • MusicLibrary - for VideoCapture audio recording
   • VideosLibrary - for VideoCapture video recording
   • WebCam - required for PhotoCapture and VideoCapture
   • Microphone - required for voice recognition
   • SpatialPerception - required for spatial mapping