2001665 - How do you prevent error "Failed to generate query template: One or more parameters still needed" when calling QaaWS with prompts?

• SAP BusinessObjects BI Platform 4.0 SP06+ deployment.
• A Query as a Web Service (QaaWS) created against a UNV Universe with @Prompt defined in the Universe exposed to the Web Service.
• Refreshing the query in the QaaWS Designer Tool returns data with no errors.
• Web Service called with all required prompt values, but returns error "Failed to generate query template: One or more parameters still needed". 
• Traces in the Dashboard Processing Server child process records the followine exception trace:
  com.sap.xcelsius.server.sdk.exception.XcelsiusServerException: Failed to generate query template: One or more parameters still needed
   at com.sap.xcelsius.server.dsl.QaaWSProcessingService.runQuery(QaaWSProcessingService.java:221)
   at com.sap.xcelsius.server.ras21.processors.internal.RunQaawsQueryProcessor.doHandle(RunQaawsQueryProcessor.java:49)
   at com.sap.xcelsius.server.ras21.processors.internal.RunQaawsQueryProcessor.doHandle(RunQaawsQueryProcessor.java:21)
   at com.sap.xcelsius.server.ras21.processors.internal.AbstractProcessorHandler.handleRequest(AbstractProcessorHandler.java:108)
   at com.sap.xcelsius.server.ras21.processors.RequestMapper.process(RequestMapper.java:83)
   at com.sap.xcelsius.server.ras21.XcelsiusProcessor.processRequest(XcelsiusProcessor.java:91)
   at com.businessobjects.ras21.servercore.requestsubsystem.RequestHandlerHelper.processRequest(RequestHandlerHelper.java:169)
   at com.businessobjects.ras21.servercore.requestsubsystem.FreeThreadedRequestHandler.handleRequest(FreeThreadedRequestHandler.java:139)
   at com.businessobjects.ras21.servercore.requestsubsystem.ProcChildWorker.post(ProcChildWorker.java:61)
   at com.businessobjects.ras21.servercore.requestsubsystem.corba.ProcChildWorkerServant$PostRunnable.run(ProcChildWorkerServant.java:159)
   at com.businessobjects.ras21.servercore.requestsubsystem.corba.ServantSpawnedThreadHelper$RealRunnable.run(ServantSpawnedThreadHelper.java:35)
   at java.lang.Thread.run(Thread.java:743)
• Traces show that the Dashboard Processing Server is invoking the processDPCommandsEx request to the Web Intelligence Processing Server with empty prompt values.
• If the Dashboard Cache and Processing Servers are stopped, to force the Web Intelligence Processing Server to directly process the QaaWS request, the following error results when the QaaWS web service is invoked:
  
  Could not connect to BusinessObjects server; Check your network connection. (XLS 000003) Unable to find servers in CMS host:port and cluster @host:port with kind dpscacheXL.Query and service BlockingDocumentConnectionRepository. All such servers could be down or disabled by the administrator. (FWM 01014) 

KBA , BI-RA-WBI , Web Intelligence , BI-RA-XL , Obsolete: BusinessObjects Dashboards and Presentation Design , How To