Adding responsibility to SYSADMIN user resulted the below error.
Oracle error - 20001: ORA-20001: FND_CANT_INSERT_USER_ROLE
(USERNAME=SYSADMIN)
(ROLENAME=FND_RESP|FND|FND_FUNC_ADMINI|STANDARD)
(ROUTINE=FND_USER_RESP_GROUPS_API.Insert_Assignment) has
been detected in FND_USER_RESP_GROUPS_API.INSERT_ASSIGNMENT
Resolution:
Issue exists in default R12 installation
Refer Oracle Note id : 454988.1
1. Run the concurrent program "Workflow Directory Services User/Role Validation" with parameters : 100000, Yes, Yes, No
2. Bounce all services under oacore or bounce opmnctl