ORA-38757: Database must be mounted and not open to FLASHBACK

Hi,

I got the error "ORA-38757: Database must be mounted and not open to FLASHBACK" on Oracle PROD database version 19.12(SunOS 5.11 sparc) with details as below:

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SQL> show parameter db_recovery_file_dest_size

NAME                 TYPE    VALUE

------------------------------------ ----------- ------------------------------

db_recovery_file_dest_size      big integer 80G

SQL> show parameter db_flashback_retention_target

NAME                 TYPE    VALUE

------------------------------------ ----------- ------------------------------

db_flashback_retention_target    integer   3600

SQL> select flashback_on from v$database;

FLASHBACK_ON

------------------

YES

SQL> CREATE RESTORE POINT DRTEST_JKE_PROD GUARANTEE FLASHBACK DATABASE;

Restore point created.

SQL> col scn format 9999999999999

col name format a30

col time format a35