UnsupportedOperationException JSF - webLogic 11g

Question

I'm developing a web application and I'm using the following versions:

• spring-core 3.1.3
• spring-webmvc 3.1.3
• spring-webflow 2.3.1
• spring-faces 2.3.1
• jsf-api 2.0.9
• jsf-impl 2.0.9
• java 1.6

The application is deployed in a WebLogic server 10.3.6. Randomly , the exception shown below is thrown while I am navigating through the application.

java.lang.UnsupportedOperationException
    at javax.faces.context.FacesContext.getPartialViewContext(FacesContext.java:165)
    at org.springframework.faces.webflow.JsfAjaxHandler.isAjaxRequestInternal(JsfAjaxHandler.java:55)
    at org.springframework.js.ajax.AbstractAjaxHandler.isAjaxRequest(AbstractAjaxHandler.java:19)
    at org.springframework.webflow.mvc.servlet.FlowHandlerAdapter.createServletExternalContext(FlowHandlerAdapter.java:216)
    at org.springframework.webflow.mvc.servlet.FlowHandlerAdapter.handle(FlowHandlerAdapter.java:192)
    at org.springframework.faces.webflow.JsfFlowHandlerAdapter.handle(JsfFlowHandlerAdapter.java:48)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:923)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:852)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882)
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:778)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
    at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:227)
    at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:125)
    at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:301)
    at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:26)
    at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:56)
    at com.jeveris.web.core.filter.log.PerformanceLogFilter.doFilter(PerformanceLogFilter.java:59)
    at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:56)
    at weblogic.servlet.internal.RequestEventsFilter.doFilter(RequestEventsFilter.java:27)
    at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:56)
    at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.wrapRun(WebAppServletContext.java:3730)
    at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3696)
    at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)
    at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:120)
    at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2273)
    at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2179)
    at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1490)
    at weblogic.work.ExecuteThread.execute(ExecuteThread.java:256)
    at weblogic.work.ExecuteThread.run(ExecuteThread.java:221)

An example of a bean:

@ManagedBean(name = "bean")
@SessionScoped
public class bean implements Serializable{
 ...
}

An example of a flow:

<?xml version="1.0" encoding="UTF-8"?>
 <flow xmlns="http://www.springframework.org/schema/webflow"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/webflow
        http://www.springframework.org/schema/webflow/spring-webflow-2.0.xsd"
    parent="parent-flow" start-state="searchDashboardState">

<on-start>          
    <evaluate expression="dashboardController.clean(flowRequestContext)" />
</on-start> 


<view-state id="searchDashboardState" view="../views/dashboard/searchDashboardView.xhtml">

    <transition on="search" to="searchDashboardState">
          <evaluate expression="dashboardController.find(flowRequestContext)" result="flowScope.dashboardData" result-type="dataModel"/>
    </transition>

</view-state>