Hello!
This is a rare error and it can happen if the ports that mcStudio uses to communicate are not opened.
mcStudio requires ports 25452 for both UDP and TCP to work properly. This is how mcStudio talks to an mcGateway and the virtual gateway. These ports should be opened during installation of mcStudio however, depending on your network/security setup, these ports may not be opened or are closed after installation.
These ports do need to be opened to work with the application