Rman import other database directory is always an error, do not know why

Import the catalog ru_catalog/123456 @ ZIDB;

Starting import catalog at 25 JUN - 17
Starting full resync of recovery catalog
Full resync complete
Connected to the source recovery catalog database
RMAN - 00571:===========================================================
RMAN - 00569:===============ERROR MESSAGE STACK FOLLOWS===============
RMAN - 00571:===========================================================
RMAN - 03002: a failure of the import the catalog command at 06/25/2017 17:28:27
RMAN - 06004: ORACLE error from recovery catalog database: ORA - 00933: the SQL command not properly ended