ORA-17628: Oracle error 19505 returned by remote Oracle server

Error:
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ORA-17628: Oracle error 19505 returned by remote Oracle server
continuing other job steps, job failed will not be re-run
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of Duplicate Db command at 10/20/2017 16:23:36
RMAN-05501: aborting duplication of target database
RMAN-03015: error occurred in stored script Memory Script
RMAN-03009: failure of backup command on ORA_DISK_1 channel at 10/20/2017 16:23:36
ORA-17628: Oracle error 19505 returned by remote Oracle server

Cause:
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db_file_name_convert value is not correctly specified.

Solution:
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db_file_name_convert='source_datafile_path', 'target_datafile_path'