What video and from where? If others can't see what URL your using they can't verify what might be the cause. And did you also try Private Mode window to verify it was should be a corrupted Browser?

https://support.mozilla.org/en-US/kb/private-browsing-use-firefox-without-history#:~:text=for%20easy%20access%3A-,Click%20the%20Menu,mode%20icon%20in%20the%20taskbar.

thanks for your reply, utube and amazon videos don't play. No I didn't try private window but will and I also reloaded firefox so its not corrupted.

Do you get an error message ? Does it help if you disable blocking auto-play via the auto-play icon at the left end of the location bar ?

• https://support.mozilla.org/en-US/kb/block-autoplay

Any relevant-looking messages in the Web Console ?

• "3-bar" menu button -> Web Developer or Tools -> Browser Tools -> Web Developer Tools
• https://firefox-source-docs.mozilla.org/devtools-user/web_console/

Did you try Firefox Troubleshoot Mode ?

Start Firefox in Troubleshoot Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration or userChrome.css is causing the problem.

• switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Themes
• do NOT click the "Refresh Firefox" button on the Troubleshoot Mode start window

• https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems