I can not watch any movie because always , it is stop

The spinning circle is the video trying to load. This could be due to low internet speed or bad wi-fi strength. Try pausing the video. If you see the grey bar at the bottom let it load for a bit before un-pausing the video. Hope that helps

Is your flash version up to date? To watch movies on iTunes (if that's what you're doing) you may need quicktime. But to watch youtube videos, you need to always keep your flash version current. Go to http://get.adobe.com/flashplayer/ to download the latest one.