Mozilla has two DRM plugins available for Firefox, as described in this article: "[[Watch DRM content on Firefox]]". I don't know which is relevant to Netflix, but could you check your Add-ons page and see if you have them? Either: * Ctrl+Shift+a * "3-bar" menu button (or Tools menu) > Add-ons In the left column, click Plugins. On the right side, can you find either: * Primetime Content Decryption Module * Widevine Content Decryption Module Normally these would be set to "Always Activate". If they are at the bottom of the list, they might need to be switched back on (changed from "Never Activate" to "Always Activate"). ---- If you cannot get native playback to work, you could use the Silverlight plugin from Microsoft. It's hard for me to tell, but I think this page also would have the Mac version (it only shows me Windows): https://www.microsoft.com/getsilverlight/