If you use extensions (Firefox/Tools > Add-ons > Extensions) that can block content (e.g. Adblock Plus, NoScript, Flash Block, Ghostery) then make sure that such extensions aren't blocking content.

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.

• Switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance
• Do NOT click the Reset button on the Safe Mode start window

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

Clear the cache and remove cookies only from websites that cause problems.

"Clear the Cache":

• Firefox/Tools > Options > Advanced > Network > Cached Web Content: "Clear Now"

"Remove Cookies" from sites causing problems:

• Firefox/Tools > Options > Privacy > "Use custom settings for history" > Cookies: "Show Cookies"

Daily Mail seems to use Flash for videos. Does Firefox show the plugin notification icon in the address bar? It looks like a small Lego block. If so, if you click it, does it show that Flash is enabled on the site? (Sample screen shot attached.)

When viewing a video, I get a pre-roll ad. Do you get the ad, or just nothing?

Could you test in Firefox's Safe Mode? That's a standard diagnostic tool to deactivate extensions and some advanced features of Firefox. More info: Diagnose Firefox issues using Troubleshoot Mode.

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?

albertcanil said

Everything used to work wonders before but since early this year the only way I can watch videos on Dail Mail and Daily Mirror is by copying the address of the article and viewing it on Chrome. I have tried updating every one of the plugins and add ons required but to no avail: they wprk on Chrome like a charm but not on Firefox

Thank you so much for your suggestion. Not in a million years would I have figured out that the ad-blocker was interfering. What I did was to simply cancel it for the sites in question. Best to you all!