!!!Avast! blocks VPN connection in Mac OS environments. {{category VPN}} When connecting from the Mac OS on which "Avast! Mac Security" (an antivirus software) is running to the VPN server of the ADC data analysis system, the connection may not be made correctly and may return to the initial state where the message "Ready to connect" is displayed. In this case, uncheck "Scan secured connections" in "Preferences > Shields > Web Shield > Settings" in the "Avast!".