ERROR: cannot launch node of type [rviz/rviz]: rviz
while I launching files in my ros groovy I have got this error message
ERROR: cannot launch node of type [rviz/rviz]: rviz
ROS path [0]=/opt/ros/groovy/share/ros
ROS path [1]=/home/unais/x_warm/src
ROS path [2]=/opt/ros/groovy/share
ROS path [3]=/opt/ros/groovy/stacks
could you know what may be the issue