Why I am getting the error below when executing a simple query from the DB Connect connection Query TAB ?

![I am using Oracle 11 release 2. I have also downloaded the corresponding JDBC driver ojdbc6.jar from the Oracle website.Whe I am trying to execute a the query SELECT 1 FROM DUAL in the query tab I get the following error. ][1] [1]: /storage/temp/63244-query.png