Are you able to play trailers?

Note that macOS 10.15 supports the current 118.0.2 Firefox release, so you can try to update to see if that version works. *https://www.mozilla.org/en-US/firefox/all/#product-desktop-release Is this about DRM protected content that uses the Widevine plugin? *https://support.mozilla.org/en-US/kb/enable-drm Anything relevant-looking in the Web Console ? *https://firefox-source-docs.mozilla.org/devtools-user/web_console/ ----- You can try these steps in case of issues with webpages: You can reload webpage(s) and bypass the cache to refresh possibly outdated or corrupted files. *hold down the Shift key and left-click the Reload button *press "Ctrl + F5" or press "Ctrl + Shift + R" (Windows,Linux) *press "Command + Shift + R" (Mac) Clear the Cache and remove the Cookies for websites that cause problems via the "3-bar" Firefox menu button (Settings). "Remove the Cookies" for websites that cause problems: *Settings -> Privacy & Security<br>Cookies and Site Data: "Manage Data" "Clear the Cache": *Settings -> Privacy & Security<br>Cookies and Site Data -> Clear Data -> [X] Cached Web Content -> Clear *https://support.mozilla.org/en-US/kb/clear-cookies-and-site-data-firefox *https://support.mozilla.org/en-US/kb/how-clear-firefox-cache Start Firefox in <b>Troubleshoot Mode</b> to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if <b>hardware acceleration</b> or if <b>userChrome.css/userContent.css</b> is causing the problem. *switch to the Default System 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 *https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop *https://support.mozilla.org/en-US/kb/smartblock-enhanced-tracking-protection *https://support.mozilla.org/en-US/kb/trackers-and-scripts-firefox-blocks-enhanced-track

It was an add-on conflict

Is this about Adblocker Ultimate ? You can consider uBlock Origin as a replacement for your current Ad blocker to see if that works better (lower memory footprint, less issues). *https://addons.mozilla.org/firefox/addon/ublock-origin/

I did turn off several add-ones including one ad-blocker and now the video player works fine. None of the ad-one I turned off are essential and I do still have an ad blocker. Thanks for the tip.