JDev :11.1.2.4 - "Page can't be displayed" when using TaskFlow as Run as Dialog Popup

In couple use cases we had to use TaskFlow behavior as 'Run as Dialog' and we used to get "Page can't be displayed" first time when we try to access TaskFlow .It works fine after that .

Adding Below context-param in web.xml has fixed our issue.

    <context-param>

        <param-name>oracle.adf.view.rich.prettyUrl.OPTIONS</param-name>

        <param-value>off</param-value>

    </context-param>