Hmm, I see the button -- I'm not logged in, but I don't see why that would make any difference.

If you add the parameter to the URL that forces list view, does it change and does the button show up?

https://www.youtube.com/user/PailinsKitchen/videos?flow=list

I can change the view using "flow=" , but the button still doesn't show up. A bit of a pain.

Maybe you've been enlisted in a UI experiment? Usually clearing cache and cookies will revert that, but as a new installation, it would be strange if those were having an effect. But... we do need to rule that out, so:

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

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 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: Do you have any add-ons in this installation of Firefox? In Safe Mode, Firefox will temporarily deactivate 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.

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? (More info: Diagnose Firefox issues using Troubleshoot Mode)