Error: 502 Bad Gateway

502 Bad Gateway : Received this notice this morning.  It occurred when I attempted to access "https://webapp-game.clubwpt.com".  I cannot access that site due to this blockage.  PRODUCT:  NORTON INTERNET SECURITY

What must be done to eliminate this block???

System:  OS Windows 7 Home Edition

Browser:  CHROME ... up to date.

NOTE: When I shut down my system, I invoked a Full System Scan and "shut down" after the scan was finished.