Well, its been a problem not loading Alexa Spary on my browser after I got an update to Firefox 20.0. Well, this was real pain for me because I used to just a website using that tool and declared to visit or not.
So, I looked all over the internet for that and found not exact solution. Some people said that disabling some plugin or addons fixed the bug but that didn’t even help me. So, I researched and found the latest Unstable version. But it works perfect as hell.
You can download the latest version from official Mozilla addons by clicking here. It shall automatically download the toolbar and you shall be ready to work with it after a cool restart of browser.