When a video issue is reported to us, nine times out of ten we can't replicate the problem on our side. We will test the playback on all browsers, devices and operating systems. We use state-of-the-art video streaming technology, and find most problems are to do with the hardware/software you're using.
Also, we have optimised our videos to play best on the Chrome browser. This is by far the world's most popular, so we have made sure that we are fully compatible with their HTML5 player. We find some folks struggle if they're using Firefox or IE.
Right off the bat, there are a few things I'd suggest you try, and these are listed here:
If nothing in that article works, then please check out this article called "Playback quality and buffering issues". And at the bottom of that page you'll see a Contact Us link, but be sure to get together everything they need to help debug the issue.
If they still can't help you, then please let us know by opening a ticket, or email us at firstname.lastname@example.org
Your help with this is crucial for us to try solve the problem, so thank you for your patience and cooperation.