Have not used Sketch for some months now, installed the latest iOS: Mavericks. But now none of the video tutorials refuse to start. Cannot learn about new features now 
What browser are you using? i just tried Safari and Chrome on Mavericks and they seemed to work ok.
You’re right: Chrome does the job. However, Safari is my standard browser and still refuses to start the video’s. Even after a fresh start-up of my Mac. Maybe there is something wrong inside which is conflicting with the Safari video-player.
But thanks for your reaction.
We see multiple issues when people are trying to access the tutorial videos on our webpage when using an out-dated internet browser.
I would suggest accessing the videos from the page below.
Hope this helps!
Patrick K.
The specific issue is a confusing one. While our videos are hosted on YouTube and use Flash or HTML5 to be displayed, for some reason on Safari if you let Microsoft Silverlight get out of date it will fail to show embedded Flash/HTML5 videos. We never specified that SketchUpChannel videos would use it, but apparently Safari uses SIlverlight to render them. It’s further confusing that without us changing our videos you can lose the ability to see them. It’s some sort of “planned obsolescence” in Microsoft Silverlight that breaks if you don’t continue to update their software.
As Patrick recommended, just visit the YouTube channel. Here is a lightly more readable URL: http://www.youtube.com/sketchupvideo
Thank you Patrick and Jody,
I had the idea that all my browsers, Silverlight and other software were up to date, but your links are working anyway.
Thanks both of you!