Whenever I tried to play a YouTube video in the most recent version of Firefox lately, it would only display the advertisement before the video for a couple of seconds before a dreaded "an error occurred, please try again later" message prevented me from watching that video or any other video for that matter on the site.
The error message was thrown on YouTube but also on third-party sites with embedded YouTube videos.
A quick analysis of the issue revealed that the error message was only displayed in Firefox, and there only if Adobe Flash Player was used to stream the videos to the browser.
The HTML5 player worked without any issues. How to find that out? You can right-click on the video to get information which technology is being used to play it.
If you see "About Adobe Flash Player" in the context menu, Flash is being used while "About the HTML5 player" indicates that HTML5 video is used instead.
What I did notice as well is that no video resolutions were displayed as available when I used the Flash Player as all were grayed out. If you monitor this closely, you will notice that the player tries each one of them and marks it as gray (unavailable).
So, switching to the HTML5 player on YouTube resolves the issue. The problem here is that it does not support all videos on the site yet. While you can play many in HTML5 format, some revert to Flash Player if installed on the system.
Here is a workaround for that
Other things you can try
While switching to HTML5 and disabling Flash worked for me, there are other things that you can try to fix the issue.
Ghacks is a technology news blog that was founded in 2005 by Martin Brinkmann. It has since then become one of the most popular tech news sites on the Internet with five authors and regular contributions from freelance writers.