Hi there, I've correctly installed Gazebo 11 on a virtual machine with Ubuntu.

I've followed the STEP 1 of the tutorial about how to create a Velodyne lidar system (this is the link http://gazebosim.org/tutorials?cat=guided_i&tut=guided_i1) till the end, where I should open the file .world just created with the instruction gazebo velodyne.world -u.

Actually, what I get is that Gazebo opens but the scene remains completely black. If I run the simulation nothing changes. However, on the left panel in the section World I can correctly see all the expected models, that is "groundplane" and "velodynehdl-32" with its associated links (base and top).

Can anybody help me, please?