computeCartesianPath() returns -21 (FRAME_TRANSFORM_FAILURE) [closed]

edit

I'm trying to do a linear motion to pick an object. This is the code:

bool RoboticArm::linearMove(geometry_msgs::Pose pose) {
move_group_ptr->setPlanningTime(10.0);

robot_state::RobotState start_state(*move_group_ptr->getCurrentState());
move_group_ptr->setStartState(start_state);


std::vector<geometry_msgs::Pose> waypoints;

geometry_msgs::Pose target_pose = pose;

target_pose.position.z -= 0.15;

waypoints.push_back(target_pose);  // down

move_group_ptr->setPoseTarget(target_pose);

move_group_ptr->setMaxVelocityScalingFactor(0.1);
move_group_ptr->setPoseReferenceFrame("/camera_rgb_optical_frame");

moveit_msgs::RobotTrajectory trajectory;
const double jump_threshold = 0.0;
const double eef_step = 0.01;
moveit_msgs::MoveItErrorCodes error_code;
double fraction = move_group_ptr->computeCartesianPath(waypoints, eef_step, jump_threshold, trajectory, true, &error_code);
ROS_INFO_NAMED("tutorial", "Visualizing plan 4 (Cartesian path) (%.2f%% acheived) err(%d)", fraction * 100.0, error_code.val);

if (move_group_ptr->execute(trajectory) != moveit::planning_interface::MoveItErrorCode::SUCCESS) {
    ROS_ERROR("Failed to plan linear motion");
    move_group_ptr->clearPoseTargets();
    move_group_ptr->setMaxVelocityScalingFactor(1.0);
    return false;
}
cout << "Linear Motion Completed" << endl;
move_group_ptr->setMaxVelocityScalingFactor(1.0);
return true;

}

We don't understant why computeCartesianPath() returns error -21. Note that knowsFrameTransform(/camera_rgb_optical_frame) returns true. Can someone help me?