Unknown Spatial Reference

Error Message

Adding data to ArcMap which does not have the coordinate system or projection defined displays the following error message:"Unknown Spatial Reference The following data sources you added are missing spatial reference information. This data can be drawn in ArcMap, but cannot be projected."

Cause

The data does not have a coordinate system or projection defined.

This message is returned for all data types which can be added to ArcMap including geodatabase feature classes, shapefiles, coverages and CAD data, as well as supported raster or image formats which do not have a coordinate system definition.

Solution or Workaround