Adobe has a test page here: https://helpx.adobe.com/flash-player.html

If there is a problem on a site, it could be a permission issue. To check whether the site is allowed to use Flash, while you're on that page with an error, you can either:

(1) click the plugin notification icon toward the left end of the address bar (typically a gray icon that looks like a small Lego block, example screenshot attached) -- this should drop a panel that tells you whether Flash is currently allowed and lets you update the permission

(2) call up the Permissions panel of the Page Info dialog using any of these:

• right-click (Mac one-button mouse: Ctrl+click) a blank area of the page and choose View Page Info > Permissions
• (menu bar) Tools menu > Page Info > Permissions
• click the padlock or "i" icon to the left of the site address, then the ">" icon, then More Information > Permissions

The top section is plugin permissions. To always allow the site, change from "Use default" to "Allow". The change is saved when you make it, so you can just close this panel after that.

Success?

See also: Why do I have to click to activate plugins?

Your solution is not working. I'll just stop using firefox, too problematic. Why should I have all these problems after upgrades when they didn't exist before the upgrades?

That's your call. I know not everyone wants to do troubleshooting or use the "quick fix" Refresh feature (Refresh Firefox - reset add-ons and settings).

Flash works the same for me in Firefox 56 as it always has, but I understand that we probably use different sites, different settings, and different add-ons, and have different experiences for that reason.

For anyone else reading this thread who might want to do a little more troubleshooting:

If a site is generally known to work in Firefox, these are general suggestions to try when it stops working correctly:

Check for Tracking Protection: Firefox may block some off-site content associated with tracking services. When it does that, it will display a shield icon toward the left end of the address bar to help you manage the feature. Please see this article for more information: What happened to Tracking Protection?.

Cache and Cookies: When you have a problem with one particular site, a good "first thing to try" is clearing your Firefox cache and deleting your saved cookies for the site.

(1) Clear Firefox's Cache

See: How to clear the Firefox cache (just the first section)

If you have a large hard drive, this might take a few minutes. If you do not see the number going down on the page, you can reload it using Ctrl+r (Mac: Command+r) to check progress.

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

• right-click (on Mac Ctrl+click) a blank area of the page and choose View Page Info > Security > "View Cookies"
• (menu bar) Tools > Page Info > Security > "View Cookies"
• click the padlock or "i" icon in the address bar, then the ">" button, then More Information, and finally the "View Cookies" button

In the dialog that opens, the current site should be pre-filled in the search box at the top of the dialog so you can remove that site's cookies individually.

Then try reloading the page. Does that help?

Testing in Firefox's Safe Mode: In its Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, and some other advanced features to help you assess whether these are causing the problem.

If Firefox is not running: Hold down the Shift key when starting Firefox. (Mac or Linux, see: Diagnose Firefox issues using Troubleshoot Mode)

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?

Do you see a Lego block icon at the left end of the location/address bar when a website uses the Shockwave Flash plugin?

If you use extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) that can block (wanted) content (e.g. Adblock Plus, NoScript, Ghostery, uBlock Origin) always make sure such extensions do not block (wanted) content.

• make sure your extensions and filters are updated to the latest version
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

I've emptied cache/cookies et al, tried 3 different sites and same problem, the only plugin I'm using is flash, I've gone through the permissions info as well to allow flash, still nothing

I do not use adblockers/extesions

Please give this a try since I have not seen it suggested. Uninstall Flash with Adobe Uninstaller https://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html then get a new one : https://get.adobe.com/flashplayer/otherversions/ Step 1: Select Operating System Step 2: Select A Version (Firefox, Win IE . . . .) Note: Other software is offered in the download. <Windows Only>

Sometimes a corruption happens and it stays corrupted even if uninstall and get a new one. Adobe Uninstaller removes more so give this a try. May want to try a Reboot after Please.

I do not see your Firefox Version ? What is it please.

Other people on Windows 7 are having issues as Microsoft not support Win7 as it should and the have decided to move to the Extended Release : https://www.mozilla.org/en-US/firefox/organizations/all/

Please let us know if this solved your issue or if need further assistance.

I've tried everything uninstalling/reinstall flash, changing permissions et al along with all the other solutions posted but nothing works. I give up.

You haven't confirmed whether you see a Lego block icon on web page where the Shockwave Flash plugin is used.

You can check the Shockwave Flash plugin here:

• http://www.adobe.com/software/flash/about/
• http://helpx.adobe.com/flash-player.html

I do not see that icon but know flash is enabled

Just to make sure you have the latest version of Flash it is version 127.0.0.159 is that correct ?? If not go to my post from before and get the Adobe Uninstaller (which you never said if used or not) .

I've already reinstalled the latest version, not helping