Reactivation failed... ffffffff error code

I am trying to reactivate my motorola defy 2. Phone purchased through straight talk. After service lapse, I applied to activate this phone using a new number and purchased a new service plan. Followed the directions on to dial ##72786#, phone restarted but failed to connect to network, error code ffffffff. Waited a while and tried again, same results. Plz help.