FND_NO_DATABASE_CONNECTION

This is the very common error in R12 instance "FND_NO_DATABASE_CONNECTION", but when you retry you won't get this error. To overcome this issue Oracle has come up with patch "9908921:R12.FWK.B Details".

Error Stack :
oracle.apps.fnd.framework.OAException: Application: FND, Message Name: FND_NO_DATABASE_CONNECTION.
at oracle.apps.fnd.framework.webui.OAPageErrorHandler.prepareException(OAPageErrorHandler.java:1251)
at oracle.apps.fnd.framework.webui.OAPageBean.preparePage(OAPageBean.java:2195)
at oracle.apps.fnd.framework.webui.OAPageBean.preparePage(OAPageBean.java:543)
at oracle.apps.fnd.framework.webui.OAPageBean.preparePage(OAPageBean.java:431)
at _OA._jspService(_OA.java:212)
at com.orionserver.http.OrionHttpJspPage.service(OrionHttpJspPage.java:59)
at oracle.jsp.runtimev2.JspPageTable.service(JspPageTable.java:390)
at oracle.jsp.runtimev2.JspServlet.internalService(JspServlet.java:594)
at oracle.jsp.runtimev2.JspServlet.service(JspServlet.java:518)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
at com.evermind.server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:734)
at com.evermind.server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:391)
at com.evermind.server.http.ServletRequestDispatcher.unprivileged_forward(ServletRequestDispatcher.java:280)
at com.evermind.server.http.ServletRequestDispatcher.access$100(ServletRequestDispatcher.java:68)

Happy Troubleshooting !!!