Are you referring to this message ?
A simulator update has been applied, please run GSX Level 2 Control Panel, and click the Disable Default Jetways button.
If yes, answer is in bold.
When you update the simulator, the default jetways ( which were disabled when installing GSX ), will be restored so, in order to prevent to see double jetways, you must disable them again and, since this cannot be done while the simulator is running, the functionality is available in the GSX Control Panel, as the message says.