IE 11 does not seem to be recognizing MSFullscreenChange. I have this code in the script:

document.addEventListener("MSFullscreenChange", function () {
        if (document.msFullscreenElement != null) {
            console.info("Went full screen");
        } else {
            console.info("Exited full screen");
        }
});

In other words, I'm using the exact code shown here on Microsoft's own site, but nothing's being printed out in the console, and I know fullscreen is enabled.

I also noticed I'm getting the SEC7118 message: XMLHttpRequest for https://gdata.youtube.com/feeds/api/videos/qywzeXowktA?v=2&alt=json required Cross Origin Resource Sharing (CORS). That wouldn't be affecting it, would it?