I am trying to add the gazebo plugin libusvgazebothrustplugin.so to my USV (Unmanned Surface Vehicle Simulation) simulation. At the moment I have my .urdf.xacro correctly working with the libusvgazebodynamicsplugin.so plugin integrated. I can launch it in a marine environment and it shows correctly both by base urdf and the urdf of my thrusters. However, when I try to add the gazebo plugin for the thrusters, for some reason it does not recognizes my links as sdf elements and shows the following error:

[ERROR] [1613244762.929272042, 0.001000000]: Could not find a engine joint by the name of in the model! [ERROR] [1613244762.929519267, 0.001000000]: Could not find a engine joint by the name of in the model!