Hi Ross, Firefox uses the Widevine plugin to work with DRM (copy protected) media. The Netflix error could be a problem with using either a too-old or a too-new version of Widevine. Since Firefox normally updates Widevine automatically in the background, this problem may go away on its own, but there may be a way to speed that up. ''Check for Updates'' As a starting point, could you check your Widevine version on the Add-ons page. Either: * Ctrl+Shift+a (Mac: Command+Shift+a) * "3-bar" menu button (or Tools menu) > Add-ons * type or paste '''about:addons''' in the address bar and press Enter/Return In the left column of the Add-ons page, click '''Plugins'''. On the right side, find Widevine and click its title to open the details tab. This is mine for comparison -- do you have this version '''4.10.2391.0''' in your Firefox? <img src="https://user-media-prod-cdn.itsre-sumo.mozilla.net/uploads/images/2021-12-02-15-52-58-f4092a.png"> If you don't have that version, click the gear icon above the details to open a little menu, then click Check for Updates. Any luck? ''Disable DRM, then Re-enable'' If that doesn't help, next thing to try would be disabling DRM on the Settings page, and then re-enabling it to try to force reinstallation of Widevine. Either: * Windows: "3-bar" menu button (or Tools menu) > Settings (previously "Options") * Mac: "3-bar" menu button (or Firefox menu) > Preferences * Linux: "3-bar" menu button (or Edit menu) > Preferences * Any system: type or paste '''about:preferences''' into the address bar and press Enter/Return to load it In the search box at the top of the page, type ''drm'' and Firefox should filter to the "Digital Rights Management" section. Uncheck the box for "Play DRM-controlled content" and Firefox should uninstall your current version of Widevine. I don't know how quickly that happens, so give it a minute. Then check the box again to trigger a fresh installation. Any luck?