The simple reason is that there is no official broker assigned for that world.
Official brokers are assigned on a world by world basis. They do not cater to all worlds across the board and as such there could be game worlds without any brokers. Please also note that brokers are players too and there could be circumstances that prevent them from putting planes on the aircraft market.
In the future, you may simply drop a note through our support system or through email
when this happens.
