Updatable materialized view- error with CREATE_SNAPSHOT_REPGROUP

Question

I'm trying to create an updatable materialized view from the replication administrators account (REPADMIN). I use the assistant and in the third step (after creating the replication group and the materialized view), when the materialized view is going to be added to the group, I got this error:
ERROR in line 1:
ORA-01403: No data found
ORA-06512: in "SYS.DBMS_REPCAT_SNA_UTL", line 5927
ORA-06512: in "SYS.DBMS_REPCAT_SNA", line 82
ORA-06512: in "SYS.DBMS_REPCAT", line 1332
ORA-06512: in "SYS.DBMS_REPCAT", line 1307
ORA-06512: in line 2
I have also tried to use the command file that the assistant generates (I add below), and the error is triggered within the CREATE_SNAPSHOT_REPOBJECT procedure.
Has anybody any idea to resolve the problem?
Thanks in advance
BEGIN
DBMS_REPCAT.CREATE_SNAPSHOT_REPGROUP(
gname => '"MYGROUP"',
master => 'DB.DOMAIN.COM',
propagation_mode => 'ASYNCHRONOUS');
END;
CREATE SNAPSHOT "MYUSER"."MYTABLE"
REFRESH COMPLETE WITH ROWID
FOR UPDATE
AS SELECT "COD", "NAME" FROM
"MYUSER"."MYTABLE"@DB.DOMAIN.COM c
BEGIN
DBMS_REFRESH.ADD(
name => '"MYUSER"."REF3"',
list => '"MYUSER"."MYTABLE"',
lax => TRUE);
END;
BEGIN
DBMS_REPCAT.CREATE_SNAPSHOT_REPOBJECT(
gname => '"MYGROUP"',
sname => '"MYUSER"',
oname => '"MYTABLE"',
type => 'SNAPSHOT',
min_communication => FALSE);
END;

Answer 1

Hello,
These days I have had some problems with my forum-account and I haven't been able to connect and reply.
Regarding to your doubt, the name of refresh group was correct, and as I see, the problem can't be related to the refresh group.
While the problem with my account was resolved, I created two new databases (*) and the problem within the materialized view process is disappeared. I suppose that my first original databases were degraded, but I don't know where.
(*) of course, I could do that because I use Oracle in an academy institution, not for production, thank God
Anyway, for now I will give up here. Thanks for your help.
Regards,