Petitions usually get administratively closed when they send an RFE (request for evidence) or other notice which requires a response and they don't get an answer. It basically means they cannot continue to process the case.
All that can be done is to file a motion to reopen. It's not necessary to get an immigration attorney, but I would consider it because getting the file reopened is the only chance to continue the process. Otherwise you would have to start over from the beginning.