Many site issues can be caused by corrupt cookies or cache. In order to try to fix these problems, the first step is to clear both cookies and the cache. Note: This will temporarily log you out of all sites you're logged in to. To clear cache and cookies do the following:

1. Go to Firefox > History > Clear recent history or (if no Firefox button is shown) go to Tools > Clear recent history.
2. Under "Time range to clear", select "Everything".
3. Now, click the arrow next to Details to toggle the Details list active.
4. From the details list, check Cache and Cookies and uncheck everything else.
5. Now click the Clear now button.

Further information can be found in the Clear your cache, history and other personal information in Firefox article.

Did this fix your problems? Please report back to us!

No, that didn't help. I tried it because you suggested it, but since Chrome has the same problem, it was a stretch to me to think that they both had a corrupted file.

I never view Groups online, but it seems to be working fine for me. I'm pretty sure http://groups.yahoo.com/neo is the new look, since Yahoo says "Thank you for being a great customer. We made changes to your Y! Groups experience. Take a quick tour."

How far do you get when launching into Groups?

Do you have any image, script, or ad blockers that could affect either of the two domains yahoo.com or yimg.com?

Well, I broke down and installed Java, and presto! Yahoo groups now show. Isn't it amazing that Yahoo would use Java when it's so darned buggy? Anyway, just because I made it, I'll show the screen shot before Java. Now, of course, all my groups show. I still hate the format, but at least I can get there.

Hi rosawood, I'm glad you fixed it. The Java install might have been a coincidence -- same time as some other changes -- since I have the Java plugins disabled and the site still works.

Could be, because Chrome doesn't support Java and now it's working. Go figure. I may never know what the problem was.