Why does urdf_spawner die?

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I am trying to run roslaunch jackal_gazebo jackal_world.launch, but I get the following error. The bit that mainly concerns me is where the urdf_spawner dies. Could anyone point out why this is?

 [ERROR] [1605532197.766520, 1517.347000]: Spawn service failed. Exiting.
[ WARN] [1605532197.766927422, 1517.347000000]: Failed to meet update rate! Took 1517.3269999999999982
[ INFO] [1605532197.821296840, 1517.347000000]: Loading gazebo_ros_control plugin
[ INFO] [1605532197.821421825, 1517.347000000]: Starting gazebo_ros_control plugin in namespace: /
[ INFO] [1605532197.822135585, 1517.347000000]: gazebo_ros_control plugin is waiting for model URDF in parameter [robot_description] on the ROS param server.
[ERROR] [1605532197.931384836, 1517.347000000]: No p gain specified for pid.  Namespace: /gazebo_ros_control/pid_gains/front_left_wheel
[urdf_spawner-11] process has died [pid 274, exit code 1, cmd /opt/ros/melodic/lib/gazebo_ros/spawn_model -urdf -model jackal -param robot_description -x 0 -y 0 -z 1.0 -R 0 -P 0 -Y 0 __name:=urdf_spawner __log:=/root/.ros/log/d7b3959a-280c-11eb-92fb-50eb712545a4/urdf_spawner-11.log].
log file: /root/.ros/log/d7b3959a-280c-11eb-92fb-50eb712545a4/urdf_spawner-11*.log
[ERROR] [1605532197.931892465, 1517.347000000]: No p gain specified for pid.  Namespace: /gazebo_ros_control/pid_gains/front_right_wheel
[ERROR] [1605532197.932310805, 1517.347000000]: No p gain specified for pid.  Namespace: /gazebo_ros_control/pid_gains/rear_left_wheel
[ERROR] [1605532197.932706629, 1517.347000000]: No p gain specified for pid.  Namespace: /gazebo_ros_control/pid_gains/rear_right_wheel
[ INFO] [1605532197.934995755, 1517.347000000]: Loaded gazebo_ros_control.