I have Xacro error related Tranmission

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My Error Message

Warning [parser.cc:950] XML Element[transmission], child of element[model] not defined in SDF. Ignoring[transmission]. You may have an incorrect SDF file, or an sdformat version that doesn't support this element.

[ WARN] [1566142242.553529670, 24.559000000]: GazeboRosJointStatePublisher Plugin (ns = //) missing <updateRate>, defaults to 100.000000

My Xacro code (2F-85 Gripper)

<?xml version="1.0"?>
<robot xmlns:xacro="http://ros.org/wiki/xacro">
  <xacro:include filename="$(find ur_description)/urdf/ur.transmission.xacro" />
  <xacro:macro name="robotiq_85"  params="prefix MAC">

    <link name="${prefix}robotiq_arg2f_base_link">
      <inertial>
        <origin xyz="-0.00013 -0.00011 0.03284" rpy="0 0 0" />
        <mass value="0.55938" />
        <inertia ixx="605783E-9" ixy="-579.95E-9" ixz="2765.53E-9" iyy="720148E-9" iyz="618E-9" izz="510534E-9" />
      </inertial>
      <visual>
        <origin xyz="0 0 0" rpy="0 0 0" />
        <geometry>
          <mesh filename="package://robotiq_2f_85/meshes/base_gripper.dae" scale="0.001 0.001 0.001"/>
        </geometry>
        <material name="Gazebo/Black">
          <color rgba="0.1 0.1 0.1 1" />
        </material>
      </visual>
      <collision>
        <origin xyz="0 0 0" rpy="0 0 0" />
        <geometry>
          <mesh filename="package://robotiq_2f_85/meshes/base_gripper.dae" scale="0.001 0.001 0.001"/>
        </geometry>
      </collision>
    </link>
    <gazebo reference="${prefix}robotiq_arg2f_base_link">
      <material>Gazebo/Black</material>
      <selfCollide>True</selfCollide>
    </gazebo>

    <link name="${prefix}left_outer_knuckle">
      <inertial>
        <origin xyz="0.01545 0 -0.00118" rpy="0 0 0" />
        <mass value="0.01252" />
        <inertia ixx="312.44E-9" ixy="0" ixz="-168.09E-9" iyy="2156E-9" iyz="0" izz="2027.51E-9" />
      </inertial>
      <visual>
        <origin xyz="0 0 0" rpy="0 0 0" />
        <geometry>
          <mesh filename="package://robotiq_2f_85/meshes/2-F-85_1_l.dae" scale="0.001 0.001 0.001"/>
        </geometry>
        <material name="Gazebo/Grey">
          <color rgba="0.1 0.1 0.1 1" />
        </material>
      </visual>
      <collision>
        <origin xyz="0 0 0" rpy="0 0 0" />
        <geometry>
          <mesh filename="package://robotiq_2f_85/meshes/2-F-85_1_l.dae" scale="0.001 0.001 0.001"/>
        </geometry>
      </collision>
    </link>
    <gazebo reference="${prefix}left_outer_knuckle">
      <material>Gazebo/Grey</material>
      <selfCollide>True</selfCollide>
    </gazebo>

    <link name="${prefix}right_outer_knuckle">
      <inertial>
        <origin xyz="-0.01545 0 -0.00118" rpy="0 0 0" />
        <mass value="0.01252" />
        <inertia ixx="312.44E-9" ixy="0" ixz="-168.09E-9" iyy="2156E-9" iyz="0" izz="2027.51E-9" />
      </inertial>
      <visual>
        <origin xyz="0 0 0" rpy="0 0 0" />
        <geometry>
          <mesh filename="package://robotiq_2f_85/meshes/2-F-85_1_r.dae" scale="0.001 0.001 0.001"/>
        </geometry>
        <material name="Gazebo/Grey">
          <color rgba="0.1 0.1 0.1 1" />
        </material>
      </visual>
      <collision>
        <origin xyz="0 0 0" rpy="0 0 0" />
        <geometry>
          <mesh filename="package://robotiq_2f_85/meshes/2-F-85_1_r.dae" scale="0.001 0.001 0.001"/>
        </geometry>
      </collision>
    </link>
    <gazebo reference="${prefix}right_outer_knuckle">
      <material>Gazebo/Grey</material>
      <selfCollide>True</selfCollide>
    </gazebo>

    <link name="${prefix}left_outer_finger">
      <inertial> ...