Error in performancepoint server

Hi friends,
  My performance point server used to work properly. but recently started showing the problems after i changed the passwords on my applications. here is the error message

An exception  occurred while rendering a Web control. The following diagnostic information might help to determine the cause of this problem:
Microsoft.PerformancePoint.Scorecards.BpmException: An unknown error has occurred. If the problem persists contact an administrator. There may be additional information in the server application event log.
   at Microsoft.PerformancePoint.Scorecards.Server.PmServer.GenerateView(Guid scorecardId, Guid configuredViewId, MemberCollection pageFilterOverrides, DictionaryWrapper`2 propertyBags)
   at Microsoft.PerformancePoint.Scorecards.WebControls.Internal.ViewTableCtrl.InitData(String scMode, String cachedGlobalStateStoreId, Guid dashboardItemId, Guid dashboardId, MemberCollection pageFilters, MemberCollection rowFilters, MemberCollection colFilters, String proxyId, String rollupType, String resourcePath, Boolean showAnnotation, Boolean showDetails)
   at Microsoft.PerformancePoint.Scorecards.WebControls.ScorecardCtrl.CreateChildControls()

Because of this my pps report on sharepoint is not working and im getting Timeout error. Can you help me resolve this issue please