After customizing airport positions and press "Y" keyboard and it closes. Then, I can't change Views not even to get back to Cockpit. I have to go back to main Menu to reload the aircraft. Am I doing something wrong?
Yes, you are using the Y key, which is NOT the key used in MSFS to close the editor. GSX in MSFS uses the ENTER key ( check the manual, they keys are not the same as P3D!! ), while Y key in MSFS enters in Slew, which has its own special camera. We don't use the Y at all in MSFS, for that reason.