StumbleUpon has released a new version of their Add-on that they claim is compatible with the latest version of Firefox. You can install it from here: https://addons.mozilla.org/en-US/firefox/addon/stumblebar-by-stumbleupon/.

Well download it from the link, and it shows in Firefox's add on folder, but still no toolbar, I looked in Toolbars to see if it was there and its not there, I tried closing and reopening Firefox which is what I've had to do in the past and still nothing,

Is it listed as "enabled" in the "Extensions" section of the add-ons page (type "about:addons" in the address bar)?

If it's enabled, you may want to contact StumbleUpon for support: http://help.stumbleupon.com/customer/portal/emails/new .

Yes it was one of the things I checked, the only thing I haven't done was shut down and reboot the entire computer.

OK, you should contact StumbleUpon for support then.

It did work but not in the way I was expecting,I found the toolbar for Stumbleupon shrunk down to a small box and in the lower left of the window, entering setting I was able to put it where it normally would've been, Thanks for your help.