If the initialization failed, you will receive one of the of the following error codes.
"
UNKNOWN_ERROR
", "UNAUTHORIZED
", "INVALID_JSON_PAYLOAD
", "UNRECOGNIZED_PROPERTY
", "INVALID_PROPERTY
", "CLIENT_ERROR
", "SERVER_ERROR
", "INVALID_TRANSACTION_STATUS
", "TRANSACTION_NOT_FOUND
", "EXPIRED_CARD
", "INVALID_CARD
", "BLOCKED_CARD
", "UNSUPPORTED_CARD
", "INVALID_ALIAS
", "INVALID_CVV
", "DUPLICATE_REFNO
", "DECLINED
", "SOFT_DECLINED
", "INVALID_SIGN
", "BLOCKED_BY_VELOCITY_CHECKER
", "THIRD_PARTY_ERROR
", "REFERRAL
", "INVALID_SETUP
".