RMAN-06429: TARGET database is not compatible version

While connecting to catalog and running RMAN script, you may face below error.

ERROR:
RMAN-06429: TARGET database is not compatible with this version of RMAN
RMAN-06618: RMAN client and database release mismatch; indicated database release is 12.1.0.2

Solution: Upgrade the catalog database as below.

1. Connect to catalog database:

rman target sys/oracle@PDBUSER catalog cat_user/pwd@TESTDB

2. Upgrade catalog:

RMAN> upgrade catalog;

recovery catalog owner is RMAN_TEST79_8
enter UPGRADE CATALOG command again to confirm catalog upgrade

RMAN> upgrade catalog;