A good internet speed would be 15mbps download speed. To see if you have this speed Click Here and run an internet speed test. If your speed does not meet 12-15mbps call your ISP and see if you could upgrade your internet service.
HAVE YOU RESET YOUR INTERNET BROWSER?
Close out and quit your browser and restart it. Make sure you clear your cache and cookies in your browser’s preferences. Also try using a different browser.
HAVE YOUR RESET YOU MODEM/ROUTER?
Try unplugging your modem and router for 30 seconds. Plug in your modem, then after 10 seconds plug your router back in. Then after about a minute try to watch again.