demo.launch from the sample demo does not work

[arunumd]

I am trying to get the sample demo provided in the demo.launch working on my Ubuntu 18.04 LTS. But it does not seem to work after following the provided instructions.

Specifically I did the following on my machine:

In the first terminal I launched:

roslaunch moveit_visual_tools demo_rviz.launch

In the second terminal, I launched:

roslaunch moveit_visual_tools demo.launch

The following is the output I get in my second terminal:

Also, my rviz is always empty like this (I can see no visualization of the demo running):