ROS1 in Windows: load_yaml direct file path works:

<xacro:ur3_robot prefix="" joint_limited="false" transmission_hw_interface="$(arg transmission_hw_interface)" kinematics_file="${load_yaml('C:\\projects\\biverse\\src\\robots\\universe\\fmauch_universal_robot\\ur_description\\config\\ur3_default.yaml')}" />

load_yaml find package method throws unicode error:

<xacro:arg name="kinematics_config" default="$(find ur_description)/config/ur3_default.yaml"/> <xacro:ur3_robot prefix="" joint_limited="false" transmission_hw_interface="$(arg transmission_hw_interface)" kinematics_file="${load_yaml('$(arg kinematics_config)')}"/>

Error:

(unicode error) 'unicodeescape' codec can't decode bytes in position 30-31: truncated \uXXXX escape (<string>, line 1) when evaluating expression 'load_yaml('$(arg kinematics_config)')'