URDF Parsing Issue with .xacro file

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Hello,

I am having issues with spawning a robot in Gazebo by using a launch file. I am running ROS Noetic on Ubuntu 20.04 with Gazebo 11. The underlying issue is that the node uses a .xacro file as robot_description. The snippet of the code can be seem here:

<arg name="urdf" default="$(find cora_description)/urdf/cora.xacro"/>

<param name="$(arg namespace)/robot_description"
             command="$(find xacro)/xacro &#x002D;&#x002D;inorder '$(arg urdf)'
             locked:=$(arg robot_locked)
             namespace:=$(arg namespace) "/>

 <!-- Spawn model in Gazebo -->
  <node name="spawn_model" pkg="gazebo_ros" type="spawn_model"
        args="-x $(arg x) -y $(arg y) -z $(arg z)
              -R $(arg R) -P $(arg P) -Y $(arg Y)
              -urdf -param $(arg namespace)/robot_description -model cora"/>

The error I get is the following:

Error [parser_urdf.cc:3183] Unable to call parseURDF on robot model
Error [parser.cc:488] parse as old deprecated model failed.

The part where I am unclear is that even though the URDF checker is running on the .xacro file that is used in the .launch file, this .xacro file includes a .urdf.xacro file (from urdf/cora.xacro):

  <!-- Robot mesh -->
  <xacro:include filename="$(find cora_description)/urdf/cora.urdf.xacro" />

I figured that because a URDF file is being included in the .xacro file, there wouldn't be an issue with the urdf parser.

I additionally ran the check_urdf command on both the urdf.xacro file mentioned above and the xacro file. The urdf.xacro file didn't return any errors while for the xacro file I had the following error:

Error:   No link elements found in urdf file
         at line 206 in /build/urdfdom-VnCcob/urdfdom-1.0.4+ds/urdf_parser/src/model.cpp
ERROR: Model Parsing the xml failed

Any help in describing what I may be missing will be helpful as this is code pulled from an open-source repo (https://github.com/osrf/vorc/) that has been widely used in other applications. I'm thinking that I may have a missing dependency or something along those lines.

Full roslaunch error output:

SUMMARY
========

PARAMETERS
 * /cora/robot_description: <?xml version="1....
 * /gazebo/enable_ros_network: True
 * /rosdistro: noetic
 * /rosversion: 1.15.11
 * /use_sim_time: True

NODES
  /
    gazebo (gazebo_ros/gzserver)
    gazebo_gui (gazebo_ros/gzclient)
    spawn_model (gazebo_ros/spawn_model)

auto-starting new master
process[master]: started with pid [20456]
ROS_MASTER_URI=http://localhost:11311

setting /run_id to 482c6b3a-1a29-11ec-bf61-81b15ac30dd6
process[rosout-1]: started with pid [20466]
started core service [/rosout]
process[gazebo-2]: started with pid [20472]
process[gazebo_gui-3]: started with pid [20478]
process[spawn_model-4]: started with pid [20483]
[ INFO] [1632152516.158574834]: Finished loading Gazebo ROS API Plugin.
[ INFO] [1632152516.159897404]: waitForService: Service [/gazebo/set_physics_properties] has not been advertised, waiting...
[ INFO] [1632152516.228341960]: Finished loading Gazebo ROS API Plugin.
[ INFO] [1632152516.229919915]: waitForService: Service [/gazebo_gui/set_physics_properties] has not been advertised, waiting...
[ INFO] [1632152517.330225530]: waitForService: Service [/gazebo/set_physics_properties] is now available.
Error [parser_urdf.cc:3183] Unable to call parseURDF on robot model
Error [parser.cc:488] parse as old deprecated model file failed.
[ERROR] [1632152527.439477, 10.006000]: Spawn service ...