This error means that your rosdep has not been initialized. rosdep is a system dependency management tool in ROS, used to install and configure required system dependency packages. Before using rosdep, you need to rosdep update initialize it through a command. This command will connect to the remote server to update the rosdep data source to obtain all supported ROS versions and platform dependency information. So the solution to this error is to run first:
sudo rosdep update
to update the data source of rosdep. After the update is complete, execute your original command again:
rosdep install --from-paths src --ignore-src --rosdistro kinetic -y --skip-keys libfranka
It will run normally. The initialization of rosdep is best completed directly after installing the new version of ROS, so that you do not need to update it every time you use rosdep in the future. You can also add rosdep update it to .bashrc or other startup scripts to ensure that it is automatically updated every time you open a new terminal. This can avoid errors caused by rosdep not being initialized.