Anyone have any ideas why this tiny code snippet throws a COM exception?

Question

System.Object obj = Activator.CreateInstance(Type.GetTypeFromProgID("esriLocation.LocatorManager"));
ILocatorManager2 locatorManager2 = obj as ILocatorManager2;
ILocatorWorkspace locatorWorkspace = locatorManager2.GetLocatorWorkspaceFromPath(@"Z:\ESRI\DataMaps10\streetmap_na");
locator = locatorWorkspace.GetLocator("Street_Addresses_US");
IAddressGeocoding addressGeocoding = (IAddressGeocoding)locator;  //this  fails

Inspecting the addressCoding object gives

'addressGeoCoding.matchFields' threw an exception of type Interop.COMException

Answer 1

check if the locator object is of the type IAddressGeocoding before casting it to that interface.

If(locator is IAdressGeocoding)
{
   IAddressGeocoding addressGeocoding = (IAddressGeocoding)locator;
}

Answer 2

With ArcEngine, you need to be sure to call IAoInitialize.Initialize when your app starts. Otherwise it throws exceptions in really strange places.

Answer 3

My .loc file was corrupted