This error occurs when using the IClassSchemaEdit::AlterClassExtensionCLSID method to register the class extension on a geocoded feature class as the GeocodedFeatureClassExtension:
"(-2147467259): Unable to initialize object class extension COM component."
This error can occur if the address fields were not copied from the address table to the geocoded feature class.
When you geocode a table of addresses using ArcObjects, you must copy the address fields from the address table to the geocoded feature class. The OriginalAddressFields property that you specify when initializing the GeocodedFeatureClassExtension has the names of the fields in the geocoded feature class that contain the address information.