DEMO_2_PANDA ROSLAUNCH ERROR

[MauryaRao1]

RLException: [rrbot_world.launch] is neither a launch file in package [rrbot_gazebo] nor is [rrbot_gazebo] a launch file name
The traceback for the exception was written to the log file

I am unable to launch the gazebo roslaunch file, the buld is successful and the demo1 works perfectly fine. The only problem arises when I run this line : roslaunch rrbot_gazebo rrbot_world.launch for the DEMO2. This is the same line mentioned in the steps