Firefox has detected that the server is redirecting the request for this address in a way that will

I am unexpectedly having this error message come up when trying to log into my WP admin using firefox. Thankfully Chrome is still working so I can get in that way. I'm afraid to touch anything for fear of breaking the site further and not being able to get in at all. (Cpanel is still working.) Is there someone who could help take a look?