Problem: Refreshing a MapService does not capture updated shapefile data
I updated my shapefile to add a new field. Why does refreshing a MapService not capture updated shapefile information?
The data source fields are only read in at load time when you first start a MapService.
Solution or Workaround
If you have only one MapService using the shapefile, refresh the MapService. In Manager, you can click Properties for the MapService and then click OK. In the Administrator, click the refresh button for the MapService.
If more than one MapService is using the shapefile, you need to remove all MapServices that use that shapefile, and then add them again.