"Failed retrieving system" Errro while connecting to Oracle DB using oracle Adapter

Hi I am trying to fetch a record from Oracle DB using Oracle Adapter after giving all transport properties correctly still says “Failed retrieving system“. The Database Service Name which I am using is correct and connection is verified but while in OracleDB Adapter Wizard it gives the error. May I know the reason why this is happening.

In Application log I got an error; “BrowsingAgent: Error trapped in constructor. No connection could be made because the target machine actively refused it. <ip address>:15000“