Problem with Reviewing contents in Criteria Workflow

[amsarkar]

I have created a criteria workflow for my website. Pages in my websites contains two parts: one conttibutor region and other is non contributor region. I have setup the criteria workflow according to content type metadata.

The problem is when i am clicking on Review workflow for those items which are not part of contributor region is throwing following error :

Content Server Request Failed 
Unable to generate HTML page. (System Error: Runtime error: java.lang.NullPointerException
at java.util.Hashtable.put(Hashtable.java:396)
at sitestudio.SSScriptExtensions.evaluateValue(Unknown Source)
at intradoc.common.DynamicHtmlMerger.computeValue(Unknown Source)
at intradoc.common.DynamicHtmlMerger.evaluateGrammarElement(Unknown Source)
at intradoc.common.DynamicHtmlMerger.substituteVariable(Unknown Source)
at intradoc.common.DynamicHtml.substituteVariable(Unknown Source)
at intradoc.common.DynamicHtml.outputHtmlEx(Unknown Source)
at intradoc.common.DynamicHtml.outputHtml(Unknown Source)
at intradoc.common.DynamicHtmlMerger.outputDynamicHtmlPage(Unknown Source)
at intradoc.server.Service.buildResponsePage(Unknown Source)
at intradoc.server.Service.doResponse(Unknown Source)
at intradoc.server.FileService.doResponse(Unknown Source)
at intradoc.server.ServiceRequestImplementor.doRequest(Unknown Source)
at intradoc.server.Service.doRequest(Unknown Source)
at intradoc.server.ServiceManager.processCommand(Unknown Source)
at intradoc.server.IdcServerThread.run(Unknown Source))

But the same is working absolutely fine for the contents which are part of contributor region.

I am using version 10gR3.

Any help would be welcome.

Thnx,
Amit