Subscription error - The user or group name not recognized(rsunknownusername)

The user or group name 'xyz\ajashadi[Unknown]' is not recognized. (rsUnknownUserName)

here xyz refers my domain and ajashadi is my username.

by the way, When you see Report Delivery Options before To,CC theres an entry called Owner which is xyz\ajashadi[Unknown]

If you have any suggestions please respond.

Thanks in advance.