As of writing this, you can do the following to enable Adobe Primetime:

1. Open your Firefox profile folder (if you don't know where your profile folder is located, type about:support into the address bar to view the support page then click the 'Open Folder' button)

2. Copy the gmp-eme-adobe folder into your profile folder. The gmp-eme-adobe folder should contain a numbered folder (probably 13, 15, or 17) and that folder should contain three files: eme-adobe.dll, eme-adobe.info and eme-adobe.voucher. Note: If you no longer have the gmp-eme-adobe folder, you can just create it. Then also create a folder named 17 inside of it. Then put the three files mentioned above inside of that folder. Those three files can be obtained here or here

3. Type about:config into the address bar to go to the config page.

4. Create the following seven Boolean entries and set them all to True: media.gmp-eme-adobe.enabled media.gmp-eme-adobe.forceSupported media.gmp-eme-adobe.visible media.gmp.decoder.enabled media.eme.enabled media.mediasource.mp4.enabled media.mp4.enabled Note: To create a Boolean entry, just right click a white area of the page, click New, then click Boolean Note: Some of the entries may already exist. In which case, you just need to make sure they're set to True (if an entry is set to False, just double-click it to change it to True).

5. Create a new Integer entry and set it to 17 (or whatever number you see in the gmp-eme-adobe folder - should be 13, 15 or 17). Note: To create an Integer entry, just right click a white area of the page, click New, then click Integer

6. While still on the config page, type media.gmp-manager.url into the config page's search bar, then double click the entry that appears below. In the text, look for /%VERSION%/ and replace it with /51.0/

7. Go to the Firefox addons page (about:addons) then click Plugins. Now right-click the Primetime entry and click Find Updates. After a few seconds, Primetime should be updated and functional. Note: If you don't see a Primetime entry amongst the installed plugins, try restarting the browser. If you still don't see it, you may have made a mistake somewhere or you may be using a version of Firefox that doesn't permit the installation of Primetime (such as a version below 38.0)

8. Go back to the config page (about:config) and find media.gmp-manager.url again. Change /51.0/ back to /%VERSION%/ Note: This step is optional. You can leave it set to /51.0/ if you don't mind the browser identifying itself as Firefox 51.0 Note: If you do change it back to /%VERSION%/ Primetime may stop working at some point in the future and you'll have to perform steps 6 and 7 again. Some things that can cause this are Firefox updates, or launching a Firefox alternative using your main Firefox profile.

For those who aren't aware (and are curious), the value of installing/enabling Primetime is that it can enable the playing of certain HTML5/H.264 media such as YouTube videos, Imgur gifv files, Reddit videos, Streamable videos and Twitter videos.

Threads started more than six months ago are auto-archived. They still come up in searches.

jscher2000 said

Threads started more than six months ago are auto-archived. They still come up in searches.

Exactly why they shouldn't be archived. This isn't the late 90's. The questions will continue to come up in search results and people may continue to have useful answers or tips for a long time to come. This outdated 'old thread' locking mentality need to go away. But I digress; I'm not here to get the system changed - just to provide a solution for this Primetime issue.

Many old threads are misleading or useless due to changes in Firefox. However, people can consult whatever they want.

If you want a thread to be indexed in Google, you need to mark a Solution.

Also, if users have Windows Media Foundation (available for Vista and later), then Firefox can decide H.264/MP4 video. See: Fix video and audio problems on Firefox for Windows N editions.

Thanks JuzBeKind, it worked for me

Hm ... I tried and could not get the workaround working in the latest firefox. Anyone knows how to fix this ridiculous tough problem. I guess this browser is dying and deservedly so. Only niche users are using it these days.

By the way, chrome works fine but I don't like the spying program planted into chrome by google itself.

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

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

johnmars888888, has own thread about using HTML5 players in Firefox at /questions/1249719