My guess is that the feature dataset is your problem. Is there a compelling reason why your featureclass(es) need to be n a feature dataset? You might try to put the feature class in a geodatabase with out it being a member of a feature dataset and see if it works.
Another trick I've recently learned (after geocoding gazillions of addresses) is to put the actual locator in a folder rather than have it stored in a geodatabase.
Hope this helps-
Please open a support call with Esri, the analyst will track this issue to resolution.
when we are publishing the web application in SOM, first we have to choose map service and after that we have to select supporting services and then add: address locator ( geo code service) and then add task as find address. and then configure. map service published sucessfully. then it will visible everything on wep maping application: like find address, results are showing.