robot_state_publisher has died, joint_state_publisher has died

edit

Hello,

I am currently learning urdf and am trying to make a two wheeled robot. I created a base link (chassis) and am trying to visualize it in rviz. To run the urdf file, i have also created a launch file. But when i run the launch file it gives me following error:

[ERROR] [1557809580.250795964]: Error reading Element value.
[robot_state_publisher-3] process has died [pid 5324, exit code 255, cmd /opt/ros/kinetic/lib/robot_state_publisher/state_publisher __name:=robot_state_publisher __log:=/home/yash/.ros/log/25ab353a-7604-11e9-856b-7c2a31390882/robot_state_publisher-3.log].
log file: /home/yash/.ros/log/25ab353a-7604-11e9-856b-7c2a31390882/robot_state_publisher-3*.log

[joint_state_publisher-2] process has died [pid 5323, exit code 1, cmd /home/yash/catkin_ws/src/joint_state_publisher/joint_state_publisher/joint_state_publisher/joint_state_publisher __name:=joint_state_publisher __log:=/home/yash/.ros/log/25ab353a-7604-11e9-856b-7c2a31390882/joint_state_publisher-2.log].
log file: /home/yash/.ros/log/25ab353a-7604-11e9-856b-7c2a31390882/joint_state_publisher-2*.log

The Launch file i am running is mentioned below:

<?xml version="1.0"?>
<launch>
    <param name="robot_description" command="cat $(find urdf_tutorial)/urdf/2wheelrobot.urdf"/>

    <node name="joint_state_publisher" pkg="joint_state_publisher" type="joint_state_publisher">
        <param name="use_gui" value="False"/>
    </node>

    <node name="robot_state_publisher" pkg="robot_state_publisher" type="state_publisher"/>
</launch>

I have searched for the solution on this forum but could not get any answers and hence i am posting this as a new question. Sometimes I also get an error saying:

invalid <param> tag: cannot load command parameter robot_description

Can anyone please guide me with the rectification of this issue?

Thanks.