Starting a Client before starting Workload Replay

[tekpr00]

Hello
iN oRACLE 11G database , I am trying to start a workload load client after calibration:
wrc sys/xxxxxxx$@enduserb mode=calibrate replaydir=/orahome/app/oracle/home/db_replay_capture

Workload Replay Client: Release 11.2.0.4.0 - Production on Fri Apr 20 12:34:40 2018

Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.


Report for Workload in: /orahome/app/oracle/home/db_replay_capture
-----------------------

Recommendation:
Consider using at least 1 clients divided among 1 CPU(s)
You will need at least 11 MB of memory per client process.
If your machine(s) cannot match that number, consider using more clients.

Workload Characteristics:
- max concurrency: 3 sessions
- total number of sessions: 5

Assumptions:
- 1 client process per 100 concurrent sessions
- 4 client processes per CPU
- 256 KB of memory cache per concurrent session
- think time scale = 100
- connect time scale = 100
- synchronization = TRUE

BUT STARTING CLIENT GAVE ERROR:
wrc system/xxxxxxx$@enduserb mode=replay replaydir=/orahome/app/oracle/home/db_replay_capture/

Workload Replay Client: Release 11.2.0.4.0 - Production on Fri Apr 20 12:36:31 2018

Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.

(wrc_main_24315.trc) ORA-15552: workload replay client cannot login to database server


I looked at the error on Metalink, it says:
ORA-15552 "workload replay client cannot login to database server"
The error ORA-15552 means workload replay client cannot login to database server.
*Cause: 1) the replay client used an invalid username or password;
        2) the replay user does not have the privilege to switch user;
        3) the recorded username does not exist in the replay database.
*Action: 1) restart replay client with correct username and password
         2) grant user switching privilege to the replay user
         3) verify whether the replay database was restored properly.

Both these users have the same passowrd.
select username from DBA_userS where username like 'SYS%';
SYSTEM
SYS

Can you highlight was is wrong here?

Thanks in advance