I had this same problem on our Samsung Blu Ray and Samsung Smart TV. It has been happening over the course of the last few weeks. All our other apps work just fine, but when I go to YouTube and click on a video, it says we aren't connected to the YouTube server. I tried all I could think of and then finally just deleted the YouTube app and downloaded it again. Now it works just fine. Maybe a glitch in getting the original version to be compatible with the Samsung update? Not sure, but try deleting the app and then re-downloading it.