RMAN Duplicate Fails ORA-38862: Flashback Database Logs Are In Use

 RMAN backup restore is failing with the following error when the flashback is turned on in the source database.

Error:
Errors in memory script
RMAN-03015: error occurred in stored script Memory Script
RMAN-06136: ORACLE error from auxiliary database: ORA-01507: database not mounted
ORA-06512: at "SYS.X$DBMS_RCVMAN", line 14894
ORA-06512: at line 1
RMAN-03015: error occurred in stored script Memory Script
RMAN-03009: failure of sql command on clone_default channel at 04/04/2021 23:37:08
RMAN-20000: abnormal termination of job step
RMAN-11003: failure during parse/execution of SQL statement: alter database flashback off
RMAN-11001: Oracle Error:
ORA-38862: Flashback database logs are in use.
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of Duplicate Db command at 04/04/2021 23:37:21
RMAN-05501: aborting duplication of target database
Recovery Manager complete.

Fix:

Update the below values on the target database and retry the clone.

SQL> alter system set db_flashback_retention_target=0 scope=both;
SQL> alter system set db_recovery_file_dest='' scope=both;

Reference  -  (Doc ID 2418803.1)