This message appears when re-mapping an object and you chose to pick the target object from the screen, but the selected object does not match the mapped objects’ hierarchy. That is, it either belongs to a different parent object or it is situated on a deeper level than the original object. After closing the message, you can either try to pick the appropriate object again, or press the Select Object button in the Update Name Mapping wizard to select the desired object from the list of objects that are currently available on the given hierarchy level.