For a specific website you can also use "Tools -> Page Info -> Permissions" to inspect and modify permissions like for Autoplay.

Did you try Firefox Safe Mode to see whether that allows to open the Autoplay Settings window?

Thanks for your reply. I did try Safe Mode, even though I was not sure that any changes I made there would be saved permanently, but the button does not work there either.

I did try looking at the permissions for an individual page and was surprised to find that if I changed that setting for a page on CNN or Yahoo News, that it seemed to change that setting for all pages from those sites, or at least it has so far. That proves to me that the 'Block Audio and Video' setting actually works properly. (To be honest, I had some doubts.)

Now all I need to do is get that setting changed for ALL web sites.

pookiesdad said

I have long been a fan of Firefox, and used to run FlashBlock when that add-on was still available. I'd like to find something similar now.

    Hello pookiesdad,

    Maybe you'd like to give this add-on a try :

    https://addons.mozilla.org/en-US/firefox/addon/noflash/

https://addons.mozilla.org/en-US/firefox/addon/disable-autoplay/ Disable HTML5 Autoplay by Afnan Khan

Disable autoplay and preloading of HTML5 video and audio players.

Thanks, McCoy, for the NoFlash link. I'm going to install it, although I think with Flash on the way out (slowly, but still...) I need something else to keep videos from playing in my browser.

Fred, I did try the HTML5 Autoplay add-on, and all I saw it do was prevent my contacts from loading when sending an e-mail in Gmail. I deleted it recently and have not noticed any difference when I'm browsing, except, of course, it's easier to address Gmail messages now.

I checked at work and found that on that machine, I was able to use the Settings button to change to Block Audio and Video, but I still had videos auto-starting on a bunch of web sites. Yahoo News is where I notice it the most lately, and the Tools pop-up says it's set to 'Block Audio and Video', even as the video is autostarting below that. (Now that I think about it, I wonder if NoFlash would help there.) This makes me wonder if using the built-in Autoplay block is even going to be worth it.

I'd still like to get this fixed, because it bugs me to have a button there that doesn't work. I've uninstalled Firefox and thought I cleared my settings before reinstalling, but that had no effect. I wouldn't have thought I'd have such trouble with a feature that's been advertised prominently in recent releases.

Had you tried with a new, clean profile?

Type about:profiles in the address bar, and Enter. Click Create a New Profile Give it a name. Do not "choose folder" Click Finish Scroll to the new profile Click Launch Profile in new Browser Close the original browser window

I did try looking at the permissions for an individual page and was surprised to find that if I changed that setting for a page on CNN or Yahoo News, that it seemed to change that setting for all pages from those sites, or at least it has so far.

Pretty sure that works at a domain level, not any specific page URL. A database for that could grow out of control quickly.