When we are developing jdeveloper application based on multiple library dependency , we make a habit of cleaning the project and building it because some time latest task flow are not refreshed properly.
However , Jdeveloper like eclipse provide us auto clean option that is not selected by default.
1. Refresh the main project viewcontroller.jpr or portal.jpr if you are working with webcenter.
2.Then select this option which will auto clean the project every time before running.