YouTube appears to have problems at present as some users have complained of the same problem of some pages failing to load or timing out. To see the real-time reports to check whether it is a global outage, you can visit such sites as DownDetector or IsItDownRightNow. Should the problem be rampant, then it most probably will be on the way out of YouTube and it ought to be redress the situation. Meanwhile, it is possible to clear your cache or reboot your router to eliminate local problems.