Models don't spawn inside a world

edit

Hello Gazebo-Users,

my target is to create a simulation with an UR5 and the Robotiq 85-Gripper. My simulation works quite fine. Now I try to insert a box that can be grabbed. Inside my world-file i wrote this:

<model name="Box4">
 <pose>0 0 2</pose>
 <static>true</static>
 <link name="Box4_Link">
  <inertial>
   <mass>5</mass>
   <inertia>
   <ixx>1.0</ixx><ixy>0</ixy><ixz>0</ixz>
   <iyy>1.0</izz><iyz>0</iyz>
   <izz>1.0</izz>
   <inertia>
  </inertial>
  <visual name="Box4_Visual">
   <geometry>
   <box>
   <size>1.05 1.05 1.05</size>
   </box>
   </geometry>
   <material>
   <script>Gazebo/SkyBlue</script>
   </material>
  </visual>
  <collision name="Box4_Collision">
   <geometry>
   <box>
   <size>0.05 0.05 0.05</size>
   </box>
   </geometry>
  </collision>
 </link>
</model>

The problem is, that the simulation starts properly, with the robot an the tables, but without the box.

Is there a need to spawn it manually?

Best regards J_Schaefer