The site asks me to activate Silverlight.

No idea why Amazon's HTML5 player doesn't support Firefox, but that seems to be the case at the moment according to this article:

http://www.amazon.com/gp/aw/help/id=201422810

The HTML5 player is available on the following browsers:

• Chrome (version M42 or newer)
• Internet Explorer (version 11 or newer)
• Microsoft Edge on Windows 10
• Opera (version 31 or newer)

When will Firefox support HTML5 for Amazon Prime Videos?

More a matter of when will Amazon support Firefox.

No Clue who needs to do what to make things work why is HTML5 working a pretty all popular Windows browsers but Firefox.

So enlighten us to what Amazon doing to prevent HTML5 working with Amazon Prime using HTML5.

Hi techmanc, Firefox will try to run the page sent by Amazon. If Amazon sends the HTML code for Silverlight instead of an HTML5 video player, then that's what Firefox has to work with.

jscher2000 said

Hi techmanc, Firefox will try to run the page sent by Amazon. If Amazon sends the HTML code for Silverlight instead of an HTML5 video player, then that's what Firefox has to work with.

OK, but this means we cannot use Firefox to watch movies on Amazon anymore because FF doesn't load Silverlight any longer. On Amazon, it's either Silverlight or DHTML5, neither of which works with FF.

It's easy to blame it on Amazon, and it's easier to just stop using FF for Amazon videos. Wait, we don't have a choice. If we want to watch Amazon Video, we simply cannot use FF any longer.

Actually, to be specific, the most pertinent question is why does Amazon work with those other browsers, and not FF? Does Amazon specifically target FF so that it will not work? If so, what is the motivation to do such?

I have this problem, except when I try to play a video, I get a message that something is stopping Silverlight from running in my browser (FF ver 42.) The complete message is below.

I have uninstalled/reinstalled Silverlight. I have run Microsoft's "Fix Silverlight corruption tool. Silverlight is installed and the plug-in is listed as "Always Activate" in the add-on manager. Nothing has fixed the problem. So I am forced to do what Amazon tech support (so-called) can recommend and use a different browser.

I have deactivated just about everything - Adblock, Flashblock, Privacy Badger, etc. Not that it all didn't work a few weeks back when I last used this PC to access Amazon.

If FF is going to change its support in important ways and say drop support for Silverlight, if it wants to be viewed as a viable commercial-level product, then it would be good if these changes were communicated IN ADVANCE to people and organizations around the net, especially those organizations that can bury you. Amazon and Facebook come to mind. Netflix. Hulu. and a few others might also make that list.

The exact message from Amazon (with details) follows: "The Silverlight plugin isn't loading and might be blocked by your browser. Show Less | Dismiss Please see the Amazon website for additional troubleshooting help. Error: 7303."

Hi throwaway, I wrote a long reply for you yesterday and I don't know what happened to it. Sorry for the delay.

First, could you make sure Silverlight is not set to "Never Activate" on the Add-ons page. Either:

• Ctrl+Shift+a (Mac: Cmd+Shift+a)
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Plugins. On the right side, look for "Silverlight Plug-In" and if it's in the grayed area at the bottom set to "Never Activate", change that to "Always Activate" or "Ask to Activate".

If it isn't there...

Firefox usually discovers Silverlight from a registry entry created by the Silverlight installer. That entry points to a file here -- can you check that the file exists:

c:\Program Files (x86)\Microsoft Silverlight\5.1.40728.0\npctrl.dll

If the file does not exist:

The installation failed. You can get a new installer from Microsoft here: https://www.microsoft.com/getsilverlight/get-started/install/default.aspx (it should be a 32-bit version since Firefox is a 32-bit browser)

If it does exist at that location:

There are a number possible reasons that Firefox might not find it:

One possible reason for an installed plugin not to apppear on the Add-ons page is if Firefox is set NOT to scan the registry for plugins. Another is that Firefox's settings file storing plugin data has become corrupted. Here are the steps to check those possibilities:

Confirm that Firefox is scanning the registry for plugins

Firefox finds the Silverlight plugin from a registry entry. Some users have the scanning turned off for some reason. Here's how to check and fix that:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful.

(2) In the filter box, type or paste scan and pause while the list is filtered

(3) If plugin.scan.plid.all is not set to its default value of true, double-click it to toggle it back to the default.

If you changed this setting, exit and restart Firefox to trigger another scan.

If you check the Add-ons page again, success?

If Firefox is set to scan but still does not find Silverlight and list it on the Add-ons page...

Remove Firefox's plugin registry file

Sometimes the pluginreg.dat file becomes corrupted. You can remove it and have Firefox re-scan for plugins. As a side effect, any plugins you have disabled on the Add-ons page probably will be re-enabled, so you'll need to go back to that page one more time.

Open your current Firefox settings (AKA Firefox profile) folder using either

• "3-bar" menu button > "?" button > Troubleshooting Information
• Help menu > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, click the "Show Folder" button to launch a new Windows Explorer window showing your settings files.

Leaving that window open, switch back to Firefox and Exit, either:

• "3-bar" menu button > "power" button
• File menu > Exit

Pause while Firefox finishes its cleanup, then rename pluginreg.dat to something like pluginreg.old

Start Firefox back up again. (If you want to restore your previous non-private session, use History > Restore Previous Session.)

When you return to the Add-ons page, is Silverlight finally there?

Thanks for the reply. The Silverlight plugin is there and is using "Always activate." I have uninstalled Slverlight from my computer restarted and reinstalled several times. No love.

I use IE Explorer to view Silverlight video from Amazon currently. No problem there.

jscher2000 said

Hi throwaway, I wrote a long reply for you yesterday and I don't know what happened to it. Sorry for the delay. First, could you make sure Silverlight is not set to "Never Activate" on the Add-ons page. Either:

• Ctrl+Shift+a (Mac: Cmd+Shift+a)
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Plugins. On the right side, look for "Silverlight Plug-In" and if it's in the grayed area at the bottom set to "Never Activate", change that to "Always Activate" or "Ask to Activate".

---

If it isn't there...

Firefox usually discovers Silverlight from a registry entry created by the Silverlight installer. That entry points to a file here -- can you check that the file exists:

c:\Program Files (x86)\Microsoft Silverlight\5.1.40728.0\npctrl.dll

If the file does not exist:

The installation failed. You can get a new installer from Microsoft here: https://www.microsoft.com/getsilverlight/get-started/install/default.aspx (it should be a 32-bit version since Firefox is a 32-bit browser)

If it does exist at that location:

There are a number possible reasons that Firefox might not find it:

One possible reason for an installed plugin not to apppear on the Add-ons page is if Firefox is set NOT to scan the registry for plugins. Another is that Firefox's settings file storing plugin data has become corrupted. Here are the steps to check those possibilities:

Confirm that Firefox is scanning the registry for plugins

Firefox finds the Silverlight plugin from a registry entry. Some users have the scanning turned off for some reason. Here's how to check and fix that:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful.

(2) In the filter box, type or paste scan and pause while the list is filtered

(3) If plugin.scan.plid.all is not set to its default value of true, double-click it to toggle it back to the default.

If you changed this setting, exit and restart Firefox to trigger another scan.

If you check the Add-ons page again, success?

If Firefox is set to scan but still does not find Silverlight and list it on the Add-ons page...

Remove Firefox's plugin registry file

Sometimes the pluginreg.dat file becomes corrupted. You can remove it and have Firefox re-scan for plugins. As a side effect, any plugins you have disabled on the Add-ons page probably will be re-enabled, so you'll need to go back to that page one more time.

Open your current Firefox settings (AKA Firefox profile) folder using either

• "3-bar" menu button > "?" button > Troubleshooting Information
• Help menu > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, click the "Show Folder" button to launch a new Windows Explorer window showing your settings files.

Leaving that window open, switch back to Firefox and Exit, either:

• "3-bar" menu button > "power" button
• File menu > Exit

Pause while Firefox finishes its cleanup, then rename pluginreg.dat to something like pluginreg.old

Start Firefox back up again. (If you want to restore your previous non-private session, use History > Restore Previous Session.)

When you return to the Add-ons page, is Silverlight finally there?

Hi dblatnik, if you click the plugin notification icon, does it confirm that Silverlight is allowed? (screen shot attached for reference)

Jscher2000, It would be nice if I saw that option. I don't. I thought that would be the "always ask" choice. Silverlight is listed as "Always Activate."

jscher2000.

Silverlight is listed in the Add-ons Manager under plugins.

Silverlight is listed as "Always Activate" As far as I can tell, Firefox is finding a VALID copy of Silverlight. (See above re: reinstall, and MS Silverlight corruption fixing tool.)

This is NOT about it never working. This is about it having STOPPED working. Recently. I don't watch a lot of Amazon video on my desktop, but if I have a lot of typing to do I might put it on in the background. And wait for a favorite scene. I would say this worked at least within the past 2 months, probably within the last 5 weeks. Something changed, and pretty much the only thing that changed in my environment was the version of Firefox. Now running version 42.0

Even with Always Activate, I think you should get the icon so that it's easy to selectively block sites. Perhaps I'm misremembering that. What about on these (semi-random selections from a search):

• http://demos.telerik.com/silverlight/
• http://bubblemark.com/silverlight2.html

Assuming the problem is limited to Amazon...

You mentioned deactivating some of the content filtering extensions. That was a logical thing to test.

How about clearing cache and Amazon cookies??

(1) Clear Firefox's Cache

See: How to clear the Firefox cache

If you have a large hard drive, this might take a few minutes.

Reload the page to see whether Amazon properly detects Silverlight. Any difference?

(2) Remove the site's cookies (save any pending work first). While viewing a page on the site, try either:

• right-click and choose View Page Info > Security > "View Cookies"
• (menu bar) Tools > Page Info > Security > "View Cookies"
• click the padlock or globe icon in the address bar > More Information > "View Cookies"

In the dialog that opens, you can remove the site's cookies individually.

Then try reloading the page (and logging in again). Any difference?

Cache is emptied automatically each time I close Firefox. I cleared it manually. No change.

All cookies are destroyed at close of FIrefox (Self-destructing Cookies add-on, Amazon cookies are allowed for the duration of a session, but are deleted at the termination of the session. ) Restarted FF - no Amazon cookies. Only cookie is related to my home page.

Any site not listed (like this one) cookies are destroyed 110 seconds after I close the last tab from that domain.

http://demos.telerik.com/silverlight/ loads a blank page (completely blank)

http://bubblemark.com/silverlight2.html tells me that it is Silverlight 2.0 animation test tells me the author's name. No player is launched.

If I do a search on the forums, it seems like there are number of folks having similar issues with Netflix. This is NOT an Amazon-only problem.

Here are the environment variables...

Windows 7 Professional, SP 1 plus important updates FF version 42 Kaspersky Labs Internet Security 2015

At one time or another I have disabled most of my add-ons, but the relevant list is:

Self-destructing Cookies 0.4.8 AdBlockPlus 2.6.11 Better Privacy 1.68.1-signed (Delete Flash local shared objects) Flashblock 1.5.18.1-signed Disconnect 3.15.3.1 (get 3rd party sites to stop tracking) Privacy Badger 1.0.3 EFF stab at privacy.

Some of these may be redundant with Privacy Badger, but I am not convinced that its heuristic approach is working. (It allows more tracking than I would like.)

Create a new profile as a test to check if your current profile is causing the problem.

See "Creating a profile":

• https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

OK I'm officially done with this "problem." Since it really isn't my problem, it is yours.

If I want to watch Amazon videos on this PC I just have to open IE or Chrome. (Both of which work.)

I am not the only person having this problem. Amazon is not the only service that is experiencing this problem. This problem is not tied up in my profile/cache/cookies/whatever.

Firefox and Silverlight and Amazon need to have some conversation. I have real work to do. Adios.

dblatnik said

OK I'm officially done with this "problem." Since it really isn't my problem, it is yours.

It's an unsolved mystery on your Firefox, but I watched a movie. Sorry we didn't find the explanation.

OK you win. I hate IE and I'm not crazy about anything from Google...

I created a new profile and it was able to play Silverlight. What/how this got corrupted I think is still a problem given the number of people complaining about Amazon and Netflix in the past few weeks. (At a guess either version 41 or 42 introduced something....)

I will at some point create the new profile and transfer passwords, and bookmarks. Addons and plugins will be added one at a time and manually to be sure they don't introduce the problem again.

Is there anything else you recommend that I transfer aside from these 2 items?

Hi dblatnik, the most common files people want to transfer are:

• places.sqlite - bookmarks+history database
• saved password files if you use that feature

To avoid site-specific blocks, I would avoid transferring permissions.sqlite.

This article has a detailed rundown of the various profile folder files: Recovering important data from an old profile.