Exception in server when using Internet Explorer, but not with Mozilla-based browsers

[gjose...@yahoo.com]

I'm getting this exception when using IExplorer to enter my webapp:
(WAS 6, IE6)

================================
SRVE0068E: Could not invoke the service() method on servlet Faces Servlet. Exception thrown : java.lang.NullPointerException
at java.util.Collections$UnmodifiableMap.<init>(Collections.java:1272)
at java.util.Collections.unmodifiableMap(Collections.java:1258)
at com.ibm.faces.context.MultipartExternalContextImpl$MultiPartServletRequestWrapper.getParameterMap(MultipartExternalContextImpl.java:525)
at com.ibm.faces.context.MultipartExternalContextImpl$MultiPartServletRequestWrapper.<init>(MultipartExternalContextImpl.java:363)
at com.ibm.faces.context.MultipartExternalContextImpl.<init>(MultipartExternalContextImpl.java:100)
at com.ibm.faces.context.MultipartFacesContextFactoryImpl.getFacesContext(MultipartFacesContextFactoryImpl.java:66)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:192)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1212)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:629)
at com.ibm.ws.webcontainer.webapp.WebAppRequestDispatcher.forward(WebAppRequestDispatcher.java:250)
at com.ibm.faces.context.MultipartExternalContextImpl.dispatch(MultipartExternalContextImpl.java:320)
at com.sun.faces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:166)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:87)
at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java(Compiled Code))
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:118)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:198)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1212)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:629)
at com.ibm.ws.webcontainer.webapp.WebApp.handleRequest(WebApp.java:2841)
at com.ibm.ws.webcontainer.webapp.WebGroup.handleRequest(WebGroup.java:220)
at com.ibm.ws.webcontainer.VirtualHost.handleRequest(VirtualHost.java:204)
at com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:1681)
at com.ibm.ws.webcontainer.channel.WCChannelLink.ready(WCChannelLink.java:77)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleDiscrimination(HttpInboundLink.java:421)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleNewInformation(HttpInboundLink.java:367)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.ready(HttpInboundLink.java:276)
at com.ibm.ws.tcp.channel.impl.NewConnectionInitialReadCallback.sendToDiscriminaters(NewConnectionInitialReadCallback.java:201)
at com.ibm.ws.tcp.channel.impl.NewConnectionInitialReadCallback.complete(NewConnectionInitialReadCallback.java:103)
at com.ibm.ws.tcp.channel.impl.WorkQueueManager.requestComplete(WorkQueueManager.java:548)
at com.ibm.ws.tcp.channel.impl.WorkQueueManager.attemptIO(WorkQueueManager.java(Compiled Code))
at com.ibm.ws.tcp.channel.impl.WorkQueueManager.workerRun(WorkQueueManager.java:934)
at com.ibm.ws.tcp.channel.impl.WorkQueueManager$Worker.run(WorkQueueManager.java:1021)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java(Compiled Code))
============================

if I use a mozilla-based browser everything is fine....
any ideas?

thanks in advance

[rene.z...@capgemini.com]

Try debugging.

And start by verifying that the GET or POST message contains the expected fields.

Then check redirects and/or cookie settings etc.