I have merged the Architectural NWC file with the current model of the building we are BIM coordinating. This NWC file was generated from a Revit model provided by the architect. Random architectural elements are missing throughout the building. For example the floor fails to show up or a random wall/ceiling in a specific room do not appear etc. I have tried using the "Unhide All" button on the Home tab and that appears to work but as soon as I save the model the random elements disappear again. Any ideas?