got the error during the failover test "Applying all logs succeeded. But starting slave failed" about mysql-master-ha HOT 3 OPEN

Is MySQL replication user (repl_use and repl_password, with REPLICATION SLAVE 
privilege) created on the new master 10.236.114.128?

Appreciate your input, sir. After I ran grant replication client on *.* to repl 
identified by 'repl'; and got the below output. I reran the failover test but 
still got the same error of "but recovery on slave partially failed". see most 
bottom for the output of the privilege setting in my dbs (FYI, have confirmed 
the output is the smae from all 3 master/master/slave dbs). 

----- Failover Report -----

app1: MySQL Master failover 10.236.114.128 to 10.236.70.129

Master 10.236.114.128 is down!

Check MHA Manager logs at MHA1DBA for details.

Started automated(non-interactive) failover.
The latest slave 10.236.70.129(10.236.70.129:3306) has all relay logs for 
recovery.
Selected 10.236.70.129 as a new master.
10.236.70.129: OK: Applying all logs succeeded.
10.236.70.131: This host has the latest relay log events.
Generating relay diff files from the latest slave succeeded.
10.236.70.131: WARN: Applying all logs succeeded. But starting slave failed.
Master failover to 10.236.70.129(10.236.70.129:3306) done, but recovery on 
slave partially failed.


mysql> SELECT Repl_slave_priv,Repl_client_priv FROM mysql.user where 
user='repl';
+-----------------+------------------+
| Repl_slave_priv | Repl_client_priv |
+-----------------+------------------+
| Y               | Y                |
+-----------------+------------------+
1 row in set (0.00 sec)

I don't have shutdown_script specified. Will that be the problem? I have very 
limited knowledge on Perl. Is there any further guide on what value or 
parameter we should set for shutdown_script and master_ip_online_change_scrip. 
Thanks a lot