OT: 404 not found from github

[Michael Hennebry]

When I try to login to github from my usual computer
(FC40) using my usual account on said computer,
I do not get asked for my user name and password,
instead I get
     404 not found
       oginx
The second line might be off.
Switching accounts on my computer
allows me to login to github.

How do I login using my usual account?
Do I really have to tell firefox to erase all of my
history and all of my cookies from the beginning of time?

If the answer is a pointer to a better forum, that is fine.