R12.1.3 : ademusr.sql - ORA-01031: insufficient privileges

Hello,

ademusr.sql - ORA-01031: insufficient privileges

Problem Description
---------------------------------------------------
I am attempting to apply Patch R12.AD.B.5(19278976).

I have run the adgrants.sql script on the database node.
The error from the adworker log is:
Start time for statement below is: Fri Jan 16 2015 12:25:16

GRANT select on WF_DEFERRED to em_oam_monitor_role

AD Worker error:
The following ORACLE error:

ORA-01031: insufficient privileges

occurred while executing the SQL statement:

GRANT select on WF_DEFERRED to em_oam_monitor_role

Error occurred in file

/u01/apps/apps_st/appl/ad/12.0.0/patch/115/sql/ademusr.sql

with arguments '&systempwd &un_fnd &pw_fnd &un_apps &pw_apps'.