Error while launching model in gazebo
I have built an urdf file from solidworks and converted the urdf to sdf as below.
<?xml version='1.0'?>
<sdf version='1.4'>
<model name='JMbot1'>
<link name='Base_plate'>
<pose>0 0 0 0 -0 0</pose>
<inertial>
<pose>-0.3317 -0.71959 -0.39019 0 -0 0</pose>
<mass>0.55378</mass>
<inertia>
<ixx>0.0061249</ixx>
<ixy>0.00016086</ixy>
<ixz>-8.6651e-18</ixz>
<iyy>0.0041631</iyy>
<iyz>-1.4656e-17</iyz>
<izz>0.010283</izz>
</inertia>
</inertial>
<collision name='Base_plate_collision'>
<pose>0 0 0 0 -0 0</pose>
<geometry>
<mesh>
<scale>1 1 1</scale>
<uri>model://JMbot1/meshes/Base_plate.STL</uri>
</mesh>
</geometry>
</collision>
<visual name='Base_plate_visual'>
<pose>0 0 0 0 -0 0</pose>
<geometry>
<mesh>
<scale>1 1 1</scale>
<uri>model://JMbot1/meshes/Base_plate.STL</uri>
</mesh>
</geometry>
</visual>
<velocity_decay>
<linear>0</linear>
<angular>0</angular>
</velocity_decay>
</link>
<link name='Castor_F'>
<pose>-0.31952 0.39256 -0.57008 -1.5708 1.1481 -6.76601e-16</pose>
<inertial>
<pose>2.2204e-16 0 0.031164 0 -0 0</pose>
<mass>0.056555</mass>
<inertia>
<ixx>2.4476e-05</ixx>
<ixy>-2.8588e-35</ixy>
<ixz>1.0281e-20</ixz>
<iyy>2.4476e-05</iyy>
<iyz>-1.2617e-20</iyz>
<izz>7.4341e-06</izz>
</inertia>
</inertial>
<collision name='Castor_F_collision'>
<pose>0 0 0 0 -0 0</pose>
<geometry>
<mesh>
<scale>1 1 1</scale>
<uri>model://JMbot1/meshes/Castor_F.STL</uri>
</mesh>
</geometry>
</collision>
<visual name='Castor_F_visual'>
<pose>0 0 0 0 -0 0</pose>
<geometry>
<mesh>
<scale>1 1 1</scale>
<uri>model://JMbot1/meshes/Castor_F.STL</uri>
</mesh>
</geometry>
</visual>
<velocity_decay>
<linear>0</linear>
<angular>0</angular>
</velocity_decay>
</link>
<joint name='Castor_F' type='revolute'>
<child>Castor_F</child>
<parent>Base_plate</parent>
<axis>
<xyz>-3.34991e-06 1 -1.50683e-06</xyz>
<limit>
<lower>-1e+16</lower>
<upper>1e+16</upper>
</limit>
<dynamics/>
</axis>
</joint>
<link name='Castor_R'>
<pose>-0.34387 0.39256 -0.86909 1.5708 -0.93144 -3.14159</pose>
<inertial>
<pose>-1.1102e-16 0 0.031164 0 -0 0</pose>
<mass>0.056555</mass>
<inertia>
<ixx>2.4476e-05</ixx>
<ixy>0</ixy>
<ixz>-3.9352e-20</ixz>
<iyy>2.4476e-05</iyy>
<iyz>-1.951e-20</iyz>
<izz>7.4341e-06</izz>
</inertia>
</inertial>
<collision name='Castor_R_collision'>
<pose>0 0 0 0 -0 0</pose>
<geometry>
<mesh>
<scale>1 1 1</scale>
<uri>model://JMbot1/meshes/Castor_R.STL</uri>
</mesh>
</geometry>
</collision>
<visual name='Castor_R_visual'>
<pose>0 0 0 0 -0 0</pose>
<geometry>
<mesh>
<scale>1 1 1</scale>
<uri>model://JMbot1/meshes/Castor_R.STL</uri>
</mesh>
</geometry>
</visual>
<velocity_decay>
<linear>0</linear>
<angular>0</angular>
</velocity_decay>
</link>
<joint name='Castor_R' type='revolute'>
<child>Castor_R</child>
<parent>Base_plate</parent>
<axis>
<xyz>-1.02941e-05 1 -2.19172e-06</xyz>
<limit>
<lower>-1e+16</lower>
<upper>1e+16</upper>
</limit>
<dynamics/>
</axis>
</joint>
<link name='Wheel_L'>
<pose>-0.46668 0.40756 -0.70859 2.512 0.081268 3.42872e-15</pose>
<inertial>
<pose>-0.039049 2.2204e-16 2.498e-15 0 -0 0</pose>
<mass>0.45064</mass>
<inertia>
<ixx>0.00091608</ixx>
<ixy>-9.6693e-19</ixy>
<ixz ...