The following error is returned when trying to define a shapefile's coordinate system that has write-access restrictions.
"Dataset already has a projection defined"
User does not have write access to the dataset.
Remove any write access restrictions applied to the shapefile as well as any folders that are part of the path to the dataset.
- Open Windows Explorer.
- Browse to the folder that contains the shapefile.
- Right-click each shapefile extension (.shp,.sbx,.dbf,.shx,.prj,.sbn) one at a time and select Properties. Or, hold down the Shift key to select all shapefile-related files.
- From the General tab on the Properties dialog, uncheck the read-only checkbox and click OK.
- The same steps apply when removing write access restrictions to folders and subfolders.