Simulation Industrial Robot and Gazebo

I followed all the steps described in the tutorial for simulating an industrial robot in ROS. When I run the plan at Rviz, it works fine. when instead I execute it always fails and I don’t see the simulation on GAZEBO which seems to be disconnected although in GAZEBO I see the robot arm. The ROS version is the NOETIC. Help me solve, thank you.

Hi @sky70

Could you please tell us the tutorial you are following?

Sorry only now i read this message. I lost the link but i have open a new message . Thank you