American FactFinder: Why did I receive a message saying that the Selected Summary Level cannot be mapped?
You will get this message when American FactFinder does not have the spatial data for the geographic level(s) you selected to map; therefore, those geographies cannot be mapped.
For example, census tracts are mappable at the county level whereas census tracts within a place (city) are not mappable. The reason for this is that census tracts can cross place boundaries whereas census tracts are wholly contained within counties. For more information on census geography, please see the Standard Hierarchy of Census Geographic Entities.