Hi, I'm going to install ROS Jade under Ubuntu 14.05 by referring to the installation instruction below (http://wiki.ros.org/jade/Installation/Ubuntu) After conducting the sudo apt-get update, I followed the guide and executed this command sudo apt-get install ros-jade-desktop-full However, the following error occurred to me here

E: Unable to locate package ros-jade-desktop-full

How can I solve this problem?