I see you also posted this question on a Linux forum, including mentioning you tried it on IE. As far as I know, IE doesn't run on Linux.
But that other post has a nice screen print showing this is a message from the Cisco webserver. And that means that it isn't a Windows 10 problem either, so this is another misplaced post. And it means only Cisco can solve it. Better contact them by phone or mail or chat and ask why you aren't allowed to login, of ask your system administrator to do that.
The autologin, by the way, might be solved by deleting a few cisco cookies or trying another browser, another profile of your current browser, another Windows account or another machine. But surely you knew that.
I recertified my CCNA and I'm trying to login to literally any of Cisco's links and this is what happens. Click login > redirects to login page > username auto populates and before I can click anything I get auto redirected > error message "Forbidden, please contact your system administrator". I can't ask this on any Cisco forums because of this auto redirect error. I've tried IE,FF, and Chrome, and it seems as soon as I type my username, and click login, it will forever just auto redirect to the forbidden page.
Ideas?

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