So, you want to watch videos on YouTube website, but it seems that Firefox is not making your life easier. Instead of playing the videos, none of them are working or loading at all. Why does this happen to YouTube on Firefox?
There may be varying reasons why you are unable to load YouTube videos on Firefox. However, we have different workarounds that might help you get past this problem and solve the error.
Some Troubleshooting Methods to Try for YouTube Loading Issues on Firefox Browser

Let’s begin with the basic solutions in troubleshooting and fixing YouTube’s loading error on Firefox web browser.
Refresh your Firefox Browser
On your Firefox browser, click the three-lined icon or the Menu button. Go to Help and choose More Troubleshooting Information. Click the Refresh Firefox button and click Refresh Firefox. Now, wait for Firefox to do its part and then click the Finish button.
Clear Firefox Cookies and Cache
To start, open the Menu settings and click Options. Head over to Privacy & Security and look for Cookies and Site Data. Now, you can click the Clear Data button. Check Cookies and Cached Web Content and click the Clear button.
Disable Add Ons on Firefox Browser
It can be that one of your browser extensions is causing the issue. You can try to figure it out by turning off all add-ons first. If the videos start loading, it is possible that an add-on is the reason for the error. Then, try to turn them back one at a time until you will see which one is the culprit.
To disable add ons on Firefox, launch the menu settings and go to Add-ons. Select Extensions. You will see the list of your extensions.
Turn Off Hardware Acceleration
On the menu settings of your Firefox browser, go to Options. Select Advanced and navigate to General. Look for the option “Use hardware acceleration when available” and uncheck the box next to it. Restart your browser.
Create a New Firefox Profile
On the address bar, type about:profiles. Click Create a New Profile. Click Next and type your desired profile name. Click Done. Now you can try loading YouTube videos with your new profile.
Update your Graphics Driver
Your graphics driver may already be outdated hence the issue coming up. You may need to install the latest version of your graphics driver before retrying the YouTube videos. If you are using a Flash Player, make sure that it is also up to date.
Wrapping Up!
Different causes may be preventing you from streaming on YouTube. But, you can always try to fix the issue by working with the methods above one at a time.