Oracle NCA protocol not running in Controller for multiple users

Hi,
 
I am facing an issue with an Oracle NCA+WebHttp protocol script that it works with 1 users but getting failed for multiple users load after login transaction.
 
It fails exactly at the line - nca_button_press("BLK_HCS0000_HCS202100_0");
 
Error is: object is not diplayed.
 
I have already tried below -
1. It's recorded in VuGen 12.01 with enabling object name for the appl.
2. I have corrleated all the values such as NCJsessionID, etc
3. Login, logout are placed as part of Action block itself.
4. Application support more than one connetion with same users Id.
 
Please let me know if any of you face this issue before. Attached is the script for your reference.
 
Is there any run time settings needs to be changed? Appreciate you response.
 
Thanks,
Shakul