EBS Rest API SOA

I have created a package in EBS to return all responsibilities through API. I created a sample package as below. When i call the API it returns the error Service execution error - Stored procedure invocation error. Error while trying to prepare and execute the APPS.XX_GETRESP_PKG.GET_RESPONSIBILITIES API. An error occurred while preparing and executing. Can someone throw some light here.

create or replace package xx_getresp_pkg as

/* $Header: $ */

/*#

* This is the Get responsibilities

* @rep:scope public

* @rep:product FND

* @rep:category BUSINESS_ENTITY Responsibility

* @rep:displayname Get responsibilities

*/

   type responsibility_rec is record ( RESPONSIBILITY_ID   varchar2