There may be unique issues with 64-bit versions of Firefox, so hopefully someone familiar with those will chime in if this standard advice isn't helpful.

Could you verify the physical presence of the plugin(s):

32-bit Firefox:

Folder: C:\Windows\SysWOW64\Macromed\Flash File: NPSWF32_18_0_0_209.dll

64-bit Firefox:

Folder: C:\Windows\system32\Macromed\Flash File: NPSWF64_18_0_0_209.dll

If that checks out:

Confirm that Firefox is scanning the registry for plugins

Firefox finds most plugins 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. Click the button promising to be careful.

(2) In the search box above the list, 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, Plugins section again, can you find Shockwave Flash there, either enabled or at the bottom disabled?

If Firefox is set to scan but still does not find the plugin 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.

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 Flash finally there?

You installed the Flash Player for Firefox and Netscape Plug-In compatible applications – NPAPI as the others is ActiveX for IE and Pepper for Chrome.

http://labs.adobe.com/downloads/flashplayer.html

James said

You installed the Flash Player for Firefox and Netscape Plug-In compatible applications – NPAPI as the others is ActiveX for IE and Pepper for Chrome. http://labs.adobe.com/downloads/flashplayer.html

Yes, I did. It was the NPAPI version.

Jscher2000, everything in your post checked out, but FF still can't detect flash, nor can a test flash website that I went to.

Just to verify, in the order you listed the solutions: File: NPSWF64_18_0_0_209.dll (but it is 19.x, as I installed Flash beta wondering if that would improve the situation any).

in about:config, plugin.scan.plid.all was and is set to default=true.

Shockwave flash is present in the plugins page of the Addons window, it is enabled, and set to ask to activate.

I renamed the pluginreg.dat, closed out FF, and restarted it. I have a new pluginreg file, but FF still can't detect Flash.

Flash always was in the plugins page of the addons window, just nowhere else. When I click the link that says Check to see if your plugins are up to date, FF says no plugins are detected. A test site to see if flash is enabled says I don't have it in the browser.

Try to run the Flash player installer as Administrator to make sure to have the permissions to modify the Windows registry.

• https://developer.mozilla.org/Add-ons/Plugins/Gecko_Plugin_API_Reference/Plug-in_Basics#How_Gecko_Finds_Plug-ins

cor-el said

Try to run the Flash player installer as Administrator to make sure to have the permissions to modify the Windows registry.

• https://developer.mozilla.org/Add-ons/Plugins/Gecko_Plugin_API_Reference/Plug-in_Basics#How_Gecko_Finds_Plug-ins

Will do that. Since I'm going to be uninstalling and resinstalling, is there a preference/recommendation to install 18 or 19?

FWIW, I used the Flash Uninstaller after shutting down FF, then installed flash 19, being sure to do it from the context menu "run as administrator," but the same issues continue.

Did you check the registry to see if the entries for the flash plugin are present?

• HKLM\Software\MozillaPlugins\@adobe.com/FlashPlayer

cor-el said

Did you check the registry to see if the entries for the flash plugin are present?

• HKLM\Software\MozillaPlugins\@adobe.com/FlashPlayer

Yes, the key called Version has the correct number: 19.0.0.133

Now there are a couple of keys above this that have upside down question marks in the data column (Description & Product Name).

paulri said

Flash always was in the plugins page of the addons window, just nowhere else.

That's different from what I thought you said originally --

When I go to the Plugins page in the Addons window, FF tells me I have no plugins installed.

So at this point Flash is set to be available -- anything other than "Never Activate" -- on the Plugins section of the Add-ons page, but is not actually available to any site?

jscher2000 said So at this point Flash is set to be available -- anything other than "Never Activate" -- on the Plugins section of the Add-ons page, but is not actually available to any site? </blockquote>

Yes, that is correct. It is available on that list, under Ask to Activate, but not available to any site.

Think I found the culprit. With e10s disabled, FF detects flash.