Error while creating MV replication group object

Hi,

I am getting error while creating replication group object. I tried to create using OEM and SQLPlus

I have attached snapshot of OEM error.

SQL> CONNECT MVIEWADMIN/MVIEWADMIN@SWEET
Connected.
SQL>
SQL> BEGIN
2 DBMS_REPCAT.CREATE_MVIEW_REPOBJECT (
3 gname => 'SCOTT',
4 sname => 'KARTHIK',
5 oname => 'emp_mv',
6 type => 'SNAPSHOT',
7 min_communication => TRUE);
8 END;
9 /
BEGIN
*
ERROR at line 1:
ORA-23306: schema KARTHIK does not exist
ORA-06512: at "SYS.DBMS_SYS_ERROR", line 86
ORA-06512: at "SYS.DBMS_REPCAT_SNA_UTL", line 2840
ORA-06512: at "SYS.DBMS_REPCAT_SNA_UTL", line 773
ORA-06512: at "SYS.DBMS_REPCAT_SNA_UTL", line 5570
ORA-06512: at "SYS.DBMS_REPCAT_SNA", line 82
ORA-06512: at "SYS.DBMS_REPCAT", line 1332
ORA-06512: at line 2

Please not already I have created KARTHIK schema.