Error - Another user has updated Opportunity header record in AS_OPPORTUNITY_PUB.Update_Opp_Header

Cause: 
While Updating opportunities using AS_OPPORTUNITY_PUB.Update_Opp_Header I am getting the below error

Another user has updated Opportunity header record. please re-query to see the changes.

The Code is 
headerRec.lead_id := leadId;
headerRec.owner_salesforce_id := resourceid;
headerRec.owner_sales_group_id :=salesGroupid;
headerRec.status :='Dropped';
headerRec.status_code :='Dropped';
headerRec.close_reason:='NOT_SPECIFIED';
headerRec.last_update_date := sysdate;
headerRec.last_updated_by := FND_GLOBAL.USER_ID;
-- dbms_output.put_line (headerRec.last_update_date );
AS_OPPORTUNITY_PUB.Update_Opp_Header(p_api_version_number => '2.0',
p_commit => fnd_api.G_FALSE,
p_header_rec => headerRec,
p_check_access_flag => 'Y',
p_admin_flag => 'N',
p_admin_group_id => null,
p_identity_salesforce_id => resourceid,
p_partner_cont_party_id => null,
x_return_status => x_return_status,
x_msg_count => x_msg_count,
x_msg_data => x_msg_data,
x_lead_id => x_lead_id);
DBMS_OUTPUT.put_line('--' || x_return_status);
IF (x_return_status != 'S') THEN
IF (fnd_msg_pub.count_msg > 0) THEN
FOR i IN 1 .. fnd_msg_pub.count_msg LOOP
fnd_msg_pub.get(p_msg_index => i,
p_encoded => 'F',
p_data => x_msg_data,
p_msg_index_out => x_msg_count);
DBMS_OUTPUT.put_line(x_msg_data);
END LOOP;

Solution:

  Get the Last_updated_date from the opportunity table for the selected opportunity and pass it to the headerRec.last_update_date

SELECT last_update_date
FROM as_leads_all
WHERE lead_id = opportunity_id;