On May 13th 2015, NCSOFT moved to a new account platform. This change required customers to migrate their accounts to this new platform before May 1st. Any accounts that were not migrated before this cutoff date have been deleted.
If you did not migrate your account but wish to continue playing Aion and/or Lineage II, you can create a new free account from the NCSOFT account page here: http://us.ncsoft.com/en/
We apologize for any frustration this may cause. Please keep in mind we are unable to recover any accounts that were not migrated by the May 1st deadline.