What are you downloading and from where (link) ?

Hi Fred - trying to do it from within Firefox under Tools > Addons

FredMcD said

link ?

url is:

about:addons

or type

Ctrl+Shift+A

Have you tried searching on the add-ons website directly? https://addons.mozilla.org/en-US/firefox/

The first one on this list is very likely what you are looking for -

https://addons.mozilla.org/en-us/firefox/search/?q=Video%20%26%20Audio%20downloader

If it isn't, use the Search Box on that page with as precise a name as you can. I had no trouble installing(and uninstalling) the selected one. Make sure you "Allow" the download.

The site nominated by the-edmeister is really the only place to start searching for Add-ons.

Thank you Alan - I think my Bitdefender Security is blocking it as "Malware" or a "Firewall" issue - will examine. I tried the above but just will not access/connect to the location. All other Internet access is fine.

Thanks also the-edmeister - that is where I was doing it from hence tools>addons from the FF browser menu bar. As my message to Alan above, will not connect - just says connecting and nothing happens.

Something easy and quick you might try - disable your Media Go Detector Plug-in.

Nope no go - will try uninstall and re-install DOH !

Oh well that was a waste of time - no change at all. Clicked on get addons again from FF browser options and all I still get is a little box that says "Loading" and that's it!

Turned off security - still no joy - will give up. Looks like it has been a known issue for YEARS. I cannot access ANY addons by any means.

Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options) key, and then starting Firefox. Is the problem still there?

While still in Safe Mode,

Type about:support in the address bar and press Enter. Under the main banner, press the button; Copy Text To Clipboard.. Then in the reply box at the bottom of this page, do a right click in the box and select Paste. This will show us your system details. No Personal Information Is Collected.

While still in safe mode, install this. You can remove it later.

Fire IE (FireIE, Enhanced IE) {web link} Embeds Internet Explorer(IE) to use the powerful Firefox add-ons. Not only an enhanced IE Tab, but also an enhanced Internet Explorer with Adblock Plus and FireGestures support. Switch to the IE engine in one click and dismiss your IE.

SORTED - I have Bitdefender Parental Control installed on my PC but it was not active via the BD control panel. Once uninstalled everything worked fine.

Thanks to all who tried to help me.

That was very good work. Well Done.