it seems a problem in macafee, cause disabling the firewall feature solves the problem

I disabled add ons and now Mozilla seems to be working fine. But..now I have no add ons. What to do?

Now I'm getting "500 Internal Server Error" when I try to open my e-mail. Other tabs I have up seem to be fine. I am very frustrated. Been working on this for hours and I thought I had it fixed. After doing some reading on here, I figured out it wasn't my computer. Which happens to be new. I thought downloaded something and got a virus. Please if any one knows what I can do to fix this....Please help. Thank you.

I tried that and it didn't work. I disabled add ons and that seemed to help. Now I'm having trouble opening my e-mail.

I tried disabling the McAfee firewall and it didn't work. I disabled Mozilla add ons and that seemed to help. Now I'm having trouble opening my e-mail (at first, I was able to).

There is an existing thread which might help you with this : see https://support.mozilla.com/en-US/questions/780053

For background information, see the Wikipedia article on HTTP Codes at http://en.wikipedia.org/wiki/List_of_HTTP_status_codes

- and, if you want more information, there's a page explaining the 500 Error HERE

In brief, the 500 means that your request has reached the server but the server cannot process it, for some unspecified reason. It is not a client-side error message.