MoveIt! Compute Cartesian path ABORTED: Solution found but controller failed during execution.

edit

I am using this robotic arm. I want to use the cartesian path planning. I start with a current position and gradually decrease the z coordinate and increase the y coordinate little by little, and append those positions to the list which I then pass to the compute_cartesian_path method. However I get an empty plan. Down below is the output of the terminal with the plan printed and the error message. How to fix this?

[ INFO] [1557217251.857413662, 9.357000000] [/move_group_commander_wrappers_1557217250468349932] [ros.moveit_ros_planning_interface.move_group_interface]: Ready to take commands for planning group arm.
[ INFO] [1557217252.075151786, 9.575000000] [/move_group] [ros.moveit_ros_move_group]: Received request to compute Cartesian path
[ INFO] [1557217252.075479483, 9.575000000] [/move_group] [ros.moveit_ros_move_group]: Attempting to follow 3 waypoints for link 'gripper_link' using a step of 0.010000 m and jump threshold 1.000000 (in global reference frame)
[ INFO] [1557217252.076646554, 9.576000000] [/move_group] [ros.moveit_ros_move_group]: Computed Cartesian path with 1 points (followed 0.000000% of requested trajectory)
joint_trajectory: 
  header: 
    seq: 0
    stamp: 
      secs: 0
      nsecs:         0
    frame_id: "/world"
  joint_names: [base_forearm_joint, forearm_0_1_joint, forearm_arm_joint, arm_0_1_joint, arm_gripper_joint]
  points: 
    - 
      positions: [0.0, 0.0, 0.0, 0.0, 0.0]
      velocities: []
      accelerations: []
      effort: []
      time_from_start: 
        secs: 0
        nsecs:         0
multi_dof_joint_trajectory: 
  header: 
    seq: 0
    stamp: 
      secs: 0
      nsecs:         0
    frame_id: ''
  joint_names: []
  points: []
[ INFO] [1557217252.079122682, 9.579000000] [/move_group] [ros.moveit_ros_move_group.ExecuteTrajectoryAction]: Execution request received
[ WARN] [1557217252.091157172, 9.590000000] [/move_group] [ros.moveit_simple_controller_manager]: Controller arm_position_controller failed with error code INVALID_GOAL
[ WARN] [1557217252.091245395, 9.591000000] [/move_group] [ros.moveit_ros_planning.trajectory_execution_manager]: Controller handle arm_position_controller reports status FAILED
[ INFO] [1557217252.091298267, 9.591000000] [/move_group] [ros.moveit_ros_planning.trajectory_execution_manager]: Completed trajectory execution with status FAILED ...
[ INFO] [1557217252.091413761, 9.591000000] [/move_group] [ros.moveit_ros_move_group.ExecuteTrajectoryAction]: Execution completed: FAILED
[ INFO] [1557217252.091589255, 9.591000000] [/move_group_commander_wrappers_1557217250468349932] [ros.moveit_ros_planning_interface.move_group_interface]: ABORTED: Solution found but controller failed during execution

EDIT

this is the code responsible for planning. When I print the waypoints, they are all correct. But the plan contains just one point at 0.

    waypoints = []

    wpose = self.move_group.get_current_pose().pose
    init_pose = copy.deepcopy(wpose)

    wpose.position.z -= 0.05
    wpose.position.y += 0.03
    waypoints.append(copy.deepcopy(wpose))

    wpose.position.z -= 0.05
    wpose.position.y += 0.03
    waypoints.append(copy.deepcopy(wpose))

    wpose.position.z -= 0.05
    wpose.position.y += 0.03
    waypoints.append(copy.deepcopy(wpose))

    print(waypoints)

    (plan, fraction) = self.move_group.compute_cartesian_path(
                                   waypoints,   # waypoints to follow
                                   0.01,        # end_effector_step, Cartesian path to be interpolated at a resolution of 1 cm
                                   1.0,         # jump_threshold
                                   avoid_collisions = True)