I am having the same problem. I have been a member of Guitar Tricks for several years. I watch lessons on a Windows based PC and everything goes well. I have a Macbook Pro and use Safari. I tried that today and the videos will not play at all. There is just a blank screen where the video lesson should be. I regularly watch news videos on all major sites. I can see Youtube all day long with no issues. There are no other websites that I go to that I cannot see there videos. In fact I can go to other online subscription guitar lesson sites and I can watch all of there videos. I JUST CANNOT WATCH GUITAR TRICKS VIDEOS ON MY MAC!!!