Hi Guillermo - I've had a good look at your scene, and rendered with AutoCAD 2015, 2016 and 2017. All of them render the artifacts you have shown. I notice in the AutoCAD preview window also shows the geometry in an odd fashion - as though the normals are flipped on the door to the washer. So I think the actual issue when the AutoCAD 2014 scene is converted to 2015 onwards, the converter is corrupting that geometry. Does that explain the problem?
Paul