Panda error using effort controllers in gripper

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Hello,

Im trying to use effort controllers in my panda gripper but it wont work. Before effort controllers, I was using follow_joint_trajectory controller and everything worked well. Now, after changing to effort_controllers/JointTrajectoryController I get an error when simulating at gazebo and Rviz.

[ERROR] [1605273071.006584287, 24.096000000]: Unable to identify any set of controllers that can actuate the specified joints: [ panda_finger_joint1 panda_finger_joint2 ]
[ERROR] [1605273071.006641908, 24.096000000]: Known controllers and their joints:
controller 'arm_controller' controls joints:
  panda_joint1
  panda_joint2
  panda_joint3
  panda_joint4
  panda_joint5
  panda_joint6
  panda_joint7
[ERROR] [1605273071.006709493, 24.096000000]: Apparently trajectory initialization failed

Using the move_it assistant, the program always adds two controllers for the hand group, as you can see here:

# Simulation settings for using moveit_sim_controllers
moveit_sim_hw_interface:
  joint_model_group: arm
  joint_model_group_pose: home
# Settings for ros_control_boilerplate control loop
generic_hw_control_loop:
  loop_hz: 300
  cycle_time_error_threshold: 0.01
# Settings for ros_control hardware interface
hardware_interface:
  joints:
    - panda_joint1
    - panda_joint2
    - panda_joint3
    - panda_joint4
    - panda_joint5
    - panda_joint6
    - panda_joint7
    - panda_finger_joint1
    - panda_finger_joint2
  sim_control_mode: 1  # 0: position, 1: velocity
# Publish all joint states
# Creates the /joint_states topic necessary in ROS
joint_state_controller:
  type: joint_state_controller/JointStateController
  publish_rate: 50
controller_list:
  - name: arm_controller
    action_ns: follow_joint_trajectory
    default: True
    type: FollowJointTrajectory
    joints:
      - panda_joint1
      - panda_joint2
      - panda_joint3
      - panda_joint4
      - panda_joint5
      - panda_joint6
      - panda_joint7
  - name: hand_controller
    action_ns: follow_joint_trajectory
    default: True
    type: FollowJointTrajectory
    joints:
      - panda_finger_joint1
      - panda_finger_joint2
hand_controller:
  type: effort_controllers/JointPositionController
  joints:
    - panda_finger_joint1
    - panda_finger_joint2
  gains:
    panda_finger_joint1:
      p: 100
      d: 1
      i: 1
      i_clamp: 1
    panda_finger_joint2:
      p: 100
      d: 1
      i: 1
      i_clamp: 1

so, I dont know how to fix this. I guess i miss something very simple but I cant find out the problem