Have you tried connecting from a direct Internet connection, and not through a VPN? I found that I only experienced this issue on my company's VPN, but not on the Internet.

I had a blank login page when I was connected to my corporate VPN. When I dropped the VPN and was directly connected to the Internet, I did not have this problem. Good luck. 

Try using an Internet connection for initial registration I had the same issue when I tried using Packet Tracer for the first time from my company's intranet. I brought my laptop home and was able to successfully log in from my Internet connection. N...