Please explain the problem in detail. What happens? What is/are the exact error message(s) ?

Make sure you are not blocking content.

Diagnose Firefox issues using Troubleshoot(Safe) Mode {web link}

A small dialog should appear. Click Start In Troubleshoot(Safe) Mode (not Refresh). Is the problem still there?

https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop

Many site issues can be caused by corrupt cookies or cache.

Warning ! ! This will log you out of sites you're logged in to. You may also lose any settings for that website.

• Delete cookies to remove the information websites have stored on your computer {web link}

• How to clear the Firefox cache {web link}

Here are the errors as reported: a) In troubleshooting mode playing Netflix video demonstrates as if loading, but hangs, and Firefox displays in a little message bar at the top: “Firefox is installing components needed to play the audio or video on this page. Please try again later.” b) Eventually, Netflix video goes to a page: “Pardon the interruption: We’re having trouble playing Netflix. Please make sure you’re using the latest version of Firefox and try again.”

Problem b) is my original issues, same as when trying to play a Netflix video in regular Firefox mode.

Problem a) happens after I delete and clean install the new Firefox version in attempt to fix the issue. I know I have had this problem beforem but that it was somehow fixed so that I only had issue b). Currently I have both issues again, and nothing has changed in two days.

I have Sophos Free security installed on MacOS, but have all shields disabled with no change.

Note that you need Widevine 4.10.2209.1 to play DRM protected media (about:plugins), older Widevine versions are no longer supported.

Try to toggle DRM off/on to see if that makes Firefox (re)load DRM components.

• Settings -> General: Play DRM
• https://support.mozilla.org/en-US/kb/enable-drm

I previously had Widevine 4.10.2209.1 and was having problem B), now in Plugins sections I cannot get a version number and I get the yellow banner underneath Widevine that says "Widevine Content Decryption Module provided by Google Inc. will be installed shortly."

Toggling 'Play DRM' in Settings does not change anything.

You should see an initial GMP XHR request and one or more redirects in the Browser Console if you toggle the DRM setting in Settings (Options/Preferences) off/on. Make sure you aren't blocking this request on the OS level.

After unchecking Play DRM-controlled content, and immediately after re-checking it, Console reports:

22:26:39.510 XHRGEThttps://aus5.mozilla.org/update/3/GMP/90.0.2/20210721174149/Darwin_x86_64-gcc3/en-US/release/Darwin 19.6.0/default/default/update.xml [HTTP/2 200 OK 92ms] 22:26:39.646 XHRGEThttps://redirector.gvt1.com/edgedl/widevine-cdm/4.10.2209.1-mac-x64.zip 22:26:39.648 1627269999648 addons.productaddons WARN Failed downloading via XHR, status: 0, reason: error 22:26:39.648 1627269999648 Toolkit.GMP ERROR GMPInstallManager.simpleCheckAndInstall Could not check for addons: {"status":"failed","results":[{"id":"gmp-widevinecdm","result":"failed"}]} Log.jsm:723 22:27:20.631 GEThttps://support.mozilla.org/en-US/questions/1344727?utm_campaign=questions-reply&utm_source=notification&utm_medium=email#answer-1429546 [HTTP/1.1 200 OK 586ms]

Comment removed due to double post.

As you can see by the lat few lines, Firefox isn't able to download the ZIP archive that contains the Widevine plugin.

• chrome://global/content/gmp-sources/widevinecdm.json
• https://redirector.gvt1.com/edgedl/widevine-cdm/4.10.2209.1-mac-x64.zip

It is possible that your security software blocks this request or you may have an hosts file, so you need to look into this.