Error while updating details through SOAP request in PB 12.5 & EASERVER 6.3.1

Hi, Greetings to all PB guru's.

Recently we have configured Easerver 6.3.1(earlier setup of 5.5) and Migrated the PB 10.5 code to 12.5.

I am trying to hit the web service through SOAP UI which calls the PB methods to update the user details and responds back.

As per my understanding all the configuration setup and datasource setup are done, but on back response from SOAP request I am getting the error as

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

   <soapenv:Body>

      <soapenv:Fault>

         <faultcode>soapenv:Server.userException</faultcode>

        <faultstring>java.rmi.RemoteException: Unregistered user</faultstring>

         <detail>

            <ns1:hostname xmlns:ns1="http://xml.apache.org/axis/">VM-STWAPP-1</ns1:hostname>

         </detail>

      </soapenv:Fault>

   </soapenv:Body>

</soapenv:Envelope>

I tried my all the possible ways to fix it but still no clue. The SOAP request on old setup(easerver 5.5) works fine on same server with different port and database.

Kindly suggest for any poosible fix for it or let me know if I have missed any configuration. As I have less exposure on the webservice end so would be good if any suggestion is in detail.

Regards,

kkr..