Update to the latest version of the player. If the Flash Player is out of date, you won't be able to play the videos properly. Solution: Check the version of Adobe Flash player that you are choosing. Are you wondering what could be the issue? It could be a problem with the flash player, problem with the plugins, HTML5 Video Player, and problem due to corrupted extensions and themes. Many users notice weird problems with YouTube not functioning in Firefox. Problem 3: YouTube player crashes every time you try to play videos Delete the YouTube cookies and the Flash videos will play again. Solution: This problem is also because of the HTML5 problem of YouTube. People facing problems of YouTube not working properly with Firefox are however not facing the issue with watching YouTube using Google Chrome or Internet Explorer. You will not face this problem with any other video sharing sites like Dailymotion and Twitch. This problem is just with a combination of Firefox and YouTube.

When you click on the play button, the video shows endless loading. When you click on any YouTube video, the red colored load bar goes directly to the end and the browser is unable to play the videos properly. Problem 2: YouTube not loading properly in Firefox If you continue to use the browser, you need to know what it supports and request the required HTML5 player on the YouTube video site. This extension is blocking the Flash Player that the YouTube videos use, which is why the YouTube videos are not playing. Solution: If you have 1.5.18 Flashblock installed in the Mozilla Firefox, it will not support the HTML player for YouTube. If this is the configuration of the browser that you are using, check out the solution for the problem below: Check if you have the following extensions on your Firefox: So, updating the browser is not the solution for running YouTube videos in Mozilla Firefox. If you have recently updated the Firefox to version 34.0.5 and 16.0.0.235 is the version of the Adobe Flash Player in your system, it will also not run YouTube Videos properly. Problem 1: YouTube Adobe Flash Player problem in Firefox YouTube Not Working on Firefox Problems and Solutions

Window.close not working in firefox