I don't know if it's a bug, or I'm missing something:
I should get the video duration when the video is ready, but with my videos it return 0, with the provided demo video it return NaN

Browser: FILL WITH YOUR BROWSER (ex: Chrome Version 46.0.2490.80, Firefox Version 3.5.6, IE 11)
Chrome

OS: FILL WITH YOUR OS (ex: Mac OS 10.11.1, iOS9, android4.5)
Windows 10

Clappr Version: 0.3.8

Steps to reproduce:

var playerElement = document.getElementById("player-wrapper");

var player = new Clappr.Player({
source: 'http://clappr.io/highline.mp4',
poster: 'http://clappr.io/poster.png',
mute: true,
height: 360,
width: 640
});

player.listenTo(player, Clappr.Events.PLAYER_READY, () => {
console.log("Video ready");
console.log(player.getDuration()) /// NaN

});

player.attachTo(playerElement);

Did you try to reproduce this issue at http://cdn.clappr.io/

YES

ps: you can attach images, logs or whatever you think might be helpful.
ps: feel free to clean this if your issue is different.