The new captcha is not shown in firefox.
Login not possible.
I guess mixed http/https could be the reason:
https://support.mozilla.org/en-US/questions/966701
Or if not search here:
https://www.google.de/search?q=captcha+does+not+work+in+firefox
What OS/version of Firefox are you using? It's showing up for me. The HTTPS issue was fixed, as this was causing it also to not show up in Chrome.