In case a user has removed three *general view overlays* the map content is not displayed. Please display below dialogs after clicking *Remove* button for *Pathways and Compartments*, *Network* and *Empty*. If user wants to delete any two of them, please display below dialog for each *remove* button click: `This contains one of the map's diagrams and is required for map display. Removing it cannot be undone.` If user wants to display the third (and last one), display below: `This contains the last of the map's diagrams. Removing it will make the map inaccessible. This action can not be undone.`