Naviswork Plugind does not work

Hi everyone:
Since the past week I have been trying the Navisworks plugin for reflect and I am having some issues:

Once I have exported the nwd to Unity, I just drop it to the hierarchy to attach it to the Reflect sync root, but there ir no visible objects in there, when i open the prefab hierarchy there are all the elements but no one has a representation in the editor (like it has no mesh or mesh renderer)