Hello jogess, try to delete the cookies to ancestry.com, and clear the cache too.

Also check if your firewall or your security software block the access for that site.

thank you

Thank you so much..Clearing the cookies and the cache did the trick. Jo

RE:Ancestry.com not working in Firefox

I just wanted to mention another possible issue regarding the failure of ancestry.com to work on FF. I followed the instructions above, and I still could not get ancestry to work in FF. Ancestry DID work in IE, but I prefer not to use IE. BTW, I am running FF 19.0.2 on Win 8. So, I started looking at my Add-ons and Plugins. To access Add-ons go to Tools-->Add-ons. Click on Add-ons, and you will be taken to your FF Add-ons page, so you can see what you have.

I disabled all of them and ancestry worked fine on FF. Then I added each one back to see which one(s) were the problem, For me, it was Ghostery 2.9.3 that was the issue. So, now I disable it whenever I go on ancestry,com. 

So, it may be the same Add-on (ghostery), or another Add-on that is giving you the problem, rather than a cache or cookie problem.

Hope this helps someone else  :D