HITL with ROS and Gazebo 7 do not work

Hello, this is my first post and I am still a new to this world so…use basic words please :sweat_smile:
I am trying to do a HITL simulation with PX4, Gazebo 7 with Kinetic ROS on a PC that run Ubuntu 16.04.
I have follow the tutorial on https://dev.px4.io/v1.9.0/en/simulation/hitl.html, but I am not able to start the simulation.
When I lunch the command

gazebo Tools/sitl_gazebo/worlds/iris.world

Gazebo start, but it get stuck on “Preparing your world” and in the background the main window of Gazebo is all black without any element.
If I open QGroundControl obviously I can’t do nothing because the simulation is not working.

I had try the SITL simulation and it works, but I am missing something with the HITL.

Can someone please help me? :pray: