Some youtube videos play while others don't

Hello, I'm having a problem with using mozillafirefox's google with youtube videos. Some have been loading faster than others while others will either load at a slow pace and stop/freeze like maybe 5-10 seconds or when I go on to play a video it'll take a few minutes just for it to start to play. Can someone help me?

Options > Privacy > Clear your recent history > Check Cookies and Cache

If that doesn't work you can try updating Java. To be honest, Youtube can be quite buggy.

I had the same problem.

To solve it install this addon for Firefox:
https://addons.mozilla.org/en-us/firefox/addon/smartvideo-for-youtube-mytube/

The issue seems to be on YouTube's side, as I've heard a lot of complaints from other people. But this addon fixed it for me, give it a try.