ERROR bad Request-Line - Force ssl - rails
Answer can be found here: How to use deactivate Webrick's SSL
you can fix it by clearing the browser cookies and it works again. It seems the authentication information is saved in the cookie and keeps reverting our requests to HTTPS but does not authenticate correctly so you get that error.
Maybe you can try:
1) stop rails server
2) rake tmp:clear
on the command line
Then start again and see if the problem persists.
UPDATE: Maybe you can try to clean any cache content / history content on your browser too.