I'm learning about electric-magnetic simulation. And I chose CST Studio Suite  as my simulation tools. But in latest version(10.0.22000.120 and 10.0.22000.100). It always raises

STARTING CST::BUS ERROR.

According to the echo message in windows terminal(when started it in windows terminal). There is some required port have been used(maybe by system, I guess). It not related to version of software according to my testing. AND......There are some interesting thing happened. I roll back to 10.0.22000.65. Found it can't work now. I found the required port is port 51777. The most interest is, there are neither firewall nor application occupied it.