Some of you who tried to login to Google Webmaster Tools over the weekend may have been out of luck. There were many reports of login errors for the Webmaster Tools system.
Those reports claimed Google was returning an error, “too many redirects.”
Google confirmed the bug and said:
I am not sure if it is fully resolved yet but if you are having issues and must access Google Webmaster Tools, use https://www.google.com/webmasters/tools instead.
Forum discussion at WebmasterWorld, DigitalPoint Forums and Google Webmaster Help.