OGG-00723
Record with class# {0,number,0}, slt# {1,number,0}, at seqno {2,number,0}, rba {3,number,0} SCN {4} has secondary transaction ID that is duplicate of existing open uncommitted transaction.
Cause
There is more than one transaction with matching secondary transaction IDs from the same thread.
Action
Restart Extract. If this does not solve the problem, contact Oracle Support.