datafile belongs to orphan incarnation

Hello,

Please help me understand why I am getting the error"datafile belongs to orphan incarnation ".I did below steps and trried to do TPITR however I am unable to bring my  tablespace online.

RMAN> recover tablespace tb2 until scn 1828656 auxiliary destination '/lvsnap/newdb/datafile/NEWDB/aux';

Starting recover at 08-MAR-15

using channel ORA_DISK_1

RMAN-05026: WARNING: presuming following set of tablespaces applies to specified point-in-time

List of tablespaces expected to have UNDO segments

Tablespace SYSTEM

Tablespace UNDOTBS1

Creating automatic instance, with SID='AFcC'

initialization parameters used for automatic instance:

db_name=NEWDB

db_unique_name=AFcC_tspitr_NEWDB