Crashes or other problems with certain multimedia content in Firefox (such as Youtube videos and Flash animations or games) can often be resolved by performing the steps in these Knowledge Base articles:

• Flash Plugin - Keep it up to date and troubleshoot problems

• Adobe Flash plugin has crashed - Prevent it from happening again

• Flash 11.3 doesn't load video in Firefox

On Windows Vista and above, you can disable Flash protected mode by following the instructions on these pages:

• http://forums.adobe.com/thread/1018071#TemporaryWorkaround
• http://kb.mozillazine.org/Flash#Disabling_Protected_Mode_in_Flash_11.3

(See this Adobe blog post for technical details about Flash protected mode.)

For recent updates for Adobe Shockwave Flash, please update your version to 14. Please refer to the security updates and Adobe Security Bulletin for more information.

Please tell us if this helped!bwechols said

I'm not getting the "click here to activate" option on Flash videos sometimes. The only site I've noticed an issue on is Yahoo news articles. And it seems that if I set Flash to "always activate" then back to "ask to activate" it will work for a while (possibly until I close the browser again?). I didn't have any issues with this until the 35.0 update.

Type about:addons<enter> in the address bar to open the Add-ons Manager. Hot key; <Control>(Mac:<Command>) <Shift> A)

On the left side of the page, select Plugins. Make sure the ones you want to use are set to Ask or Allow.

Go to the web page. Once the page is loading, mouse to the address bar and Left click the icon. A window for displaying site information should come up. Select More Information. Now select Permissions. In the menu, Make sure the ones you want to use are set to Ask or Allow.

It is possible that the Shockwave Flash plugin is not used, but the HTML5 media player player is used instead.

Disabling "protected mode" seems to have mostly cured the issue.

Ironically, this Adobe page won't do anything when I click the "Activate Adobe Flash" link, but it looks like I can mostly live with the issues now.

Any idea what I can do to get "protected mode" to work, because it seems like a good feature to have from what I've read about it.

Note that in Firefox 35 you can toggle this pref to true on the about:config page to disable protected mode in the Shockwave Flash plugin:

• dom.ipc.plugins.flash.disable-protected-mode = true
• http://www.ghacks.net/2014/12/21/how-to-disable-flash-player-protected-mode-in-firefox/

bwechols said

Disabling "protected mode" seems to have mostly cured the issue. Ironically, this Adobe page won't do anything when I click the "Activate Adobe Flash" link, but it looks like I can mostly live with the issues now.

Try reloading the page and then see if clicking the "Activate Adobe Flash" link lets you allow Flash, as suggested here:

• /questions/1042082 Firefox 35.0 not playing flash when set to activate

Since you wrote that your issues are mostly solved and you can live with the rest, I'll mark this question "solved".