About .prj files
If the geographic data in a Shapefile is not referenced by latitude and longitude, it must include a file ending in .prj that tells Magic Maps about the Shapefile's coordinate reference system. Magic Maps only accepts .prj files that are formatted as Well-Known Text (WKT). More information about .prj files can be found on Wikipedia.
If Magic Maps is unable to parse a particular .prj file, it will produce an error in the system log file (Applications > Utilities > Console > system.log).
See also: