I tried to accept my invite to HQ, and now my screen is completely blank.

Sometimes, your screen may go completely blank after selecting "Visit this link" to accept your invite. Usually, your invite has been successfully accepted, even if you are not seeing anything. If your screen is completely blank after accepting your invite to HQ, simply try refreshing your browser. If your screen remains blank, go back to the HQ login screen and logien using the email address the invite was sent to.