Error message step by step registration

I am getting following message as error message when tabbing from username field to next field upon registration:

Session expired or cookies are not enabled in your browser. Please press "reload page" in your browser, and enable cookies in your browser.

Neither relaoding or enabling cookies makes this message disappear. What is this about?

I have no idea what made this error appear. But after a complete restart it disappeared.

CB has spoof checking features. This is usually handled by a session value or a cookie. It's to ensure the a secure post can't be sent more than once and to ensure that a session that has expired or set for too long can't post. General a refresh of the page you were previously on will refresh the spoof token and it'll work fine again.