Replication :: Setting Replication Table Does Not Exist Or Is Invalid

I want to set up advance replication for 3 master site (multimaster) I created 3 master site named orc1,orc2,orc3 and followed up oracle replication management of API book instruction I created 2 tables(tes1,test2) in hr schema in all 3 master site with the same data. then I created the following steps

1-CONNECT repadmin/repadmin@orc1

2-Create the master group named hr_test_repg

BEGIN
DBMS_REPCAT.CREATE_MASTER_REPGROUP(
gname => 'hr_test_repg');
END;
/

4-add tables test1 and test2 to the group

BEGIN
DBMS_REPCAT.CREATE_MASTER_REPOBJECT(
gname => 'hr_test_repg',
type => 'TABLE',
oname => 'test1',

[code]....

I could create DBMS_REPCAT.GENERATE_REPLICATION_SUPPORT for test2 but not for test1 and it produces error

RROR at line 1:
RA-23309: object hr.test1 of type TABLE exists
RA-06512: at "SYS.DBMS_SYS_ERROR", line 105
RA-06512: at "SYS.DBMS_REPCAT_MAS", line 2552
RA-06512: at "SYS.DBMS_REPCAT", line 562
RA-06512: at line 2