Trouble Loading Different Worlds with PX4 and Gazebo 9.15

Hello, I am completely new to Gazebo and PX4. My environment is:
Ubuntu 20.04
Gazebo 9.15

I installed PX4 by doing:

~$ mkdir src && cd src
~/src$ git clone
~/src$ cd Firmware
~/src/Firmware$ make px4_sitl gazebo_lander
(lander is a custom model)

This works perfectly fine and I can open the When I try to open any other world, I get the error:

~/src/Firmware$ make px4_sitl gazebo_lander__sonoma_raceway
ninja: error: unknown target ‘gazebo_lander__sonoma_raceway’
make: *** [Makefile:226: px4_sitl] Error 1

This happens to every world. Does anyone know what I’m doing wrong?

Thank you very much for your time.

  • Thanh Tran