It's just that the cache takes up too much. Just clean it up.
There may be something wrong with your flash player plug-in or the version is too low. Personally, I suggest you use 360 software housekeeper to upgrade or reinstall this plug-in that should be able to solve. Guess the reason is the network quality problem, and the buffered video is too poor; Please reinstall Adobe flash player.
Have you measured the internet speed? The DNS server set it up, right?
Either there is something wrong with the video itself.
Hope to adopt!