The geocoder data may be missing, or the link to the geocoder locator is broken.
Browse to ...Program Files\ArcGIS\Business Analyst\Data\USA Geocoding Service and verify the geocoder data is present.
If the data is present, resetting the link to the locator should fix the problem. From the Business Analyst drop-down menu, select Preferences and select the Dataset tab. Click the browse button next to Choose an address locator and browse to C:\Program Files\ArcGIS\Business Analyst\Data\USA Geocoding Service. Select the default locator (USA Geocoding Service). If you have a custom locator, point to the file instead.