RobotStudio event

Can't communicate with robots by RS

Hello,
From last week RS5.11(online) can't connect to robot system. I could do that until 2 weeks before. I tried on some robot systems I could connect. It's not only me. Some other colleague PC have the same trouble. We guess Mcafee may be blocking. So we set it to unblock though it failed. Anybody has the information on that?

BR
Yu