I am posting this in A330 section as it appears to be the most popular one, but this bug concerns all default planes developed by iniBuilds. Basically, the game won't go back to main menu after pressing END FLIGHT and freezes indefinitely. It was reported by many users on the official forum, please see link below.
Ending a flight after flying any other plane (default or 3rd party) always loads the main menu just fine, only iniBuilds planes cause this issue for some reason.
My video showing this bug in action. I trimmed it to minimum but the screen you see at the end was there for 40min, until I killed the game process in task manager.
Sim freezes when returning to main menu with inibuilds aircraft - Bug Reporting Hub / Install, Performance & Graphics - Microsoft Flight Simulator Forums