This post contains complete directions that help fix error code 0xA00F4246 while trying to launch the Webcam device in your Windows 10 or Windows Phone.
For Windows 10: Method 1: run the Hardware and Devices troubleshooter Method 2: update the Camera driver for your Integrated webcam from Device Manager Restart when ready.
Method 3: Run Integrated webcam driver (setup file) in compatibility mode. You may refer to the below post@ www.dell.com/support/article/us/en/4/SLN85507#W103 Take running ccsetup525 as an example... Tip: select Windows 8/8.1 operating system. Method 4: Uninstall -> restart > reinstall the webcam and audio drivers
Other options: 1) install the "media feature pack for N and KN versions of windows 10" (aka, KB3010081) www.microsoft.com/en-us/download/details.aspx?id=48231 2) contact the Webcam manufacturer and replace the camera you're using.
For WP users:
Option 1: Try resetting your Windows Phone: Settings -> Device Information -> Reset