Crystal Reports Unknown error 0x8004380D

Message

   I have a problem we have make a Report with CR XI when we debug the VS 2005 web application where we have put in the reports then evrithing go fine. But when we put the web application on a web server come the Server Error 

[COMException (0x80004005): Unknown error 0x8004380D]
   CrystalDecisions.ReportAppServer.Prompting.IPromptEngine.startPrompting(PromptingUnits units, CRPromptingInfoProvider infoProvider, PromptingOption option) +0
   CrystalDecisions.ReportSource.EromReportSourceBase.DoParameterPrompting(PromptingRequestContext reqContext) +321
   CrystalDecisions.CrystalReports.Engine.FormatEngine.DoParameterPrompting(PromptingRequestContext reqContext) +44
   CrystalDecisions.ReportSource.LocalReportSourceBase.DoParameterPrompting(PromptingRequestContext reqContext) +140
   CrystalDecisions.Web.ReportAgentBase.DoPrompting(PromptingHTMLRenderOption htmlOption) +121
   CrystalDecisions.Web.CrystalReportViewer.OnPreRender(EventArgs e) +966
   System.Web.UI.Control.PreRenderRecursiveInternal() +80
   System.Web.UI.Control.PreRenderRecursiveInternal() +171
   System.Web.UI.Control.PreRenderRecursiveInternal() +171
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +842

can enybody help us ?? 