When upgrade Connections db, there is warning like insufficient privileges.
Connect to related database, use select * from syscat.dbauth
It can be seen that the Admin user is changed to some other user.
It is found that customer changed default DB2 admin user from Administrator to some other user else. This cause
Inside the Connections upgrade sql scripts, find " Connect to <DB_NAME>", then modify it to " Connect to <DB_NAME> user <User_NAME> using <USER_PASSWORD>. "
Then re-run the scrips.