• Open the project
• Generate the code and the designer will throw this exception.
• This works in LLBLGen Pro 5.5.

Exception information.
=============================================================
LLBLGen Pro version: v5.9. Build: 5.9.2

Exception details:
=====================
Message: Object reference not set to an instance of an object.
Source: LptTAfe7d87601ac54d5aac75c7c0e3d7a9be
Stack trace: 
   at SD_DTO_RootDerivedElementReadOnlyPersistence.ConstructCorrelationPredicate(Pair`2 correlationRelationship, String outerQueryAlias)
   at SD_DTO_RootDerivedElementReadOnlyPersistence.ProduceDocumentProjectorQs(String baseQueryName, String documentNameForOutput, DocumentDefinitionBase document, IGenerator executingGenerator, SourceNavigatorPath lambdaScopePath, String typesNamespace, Int32 numberOfRootTabs, Boolean inlineValueTypeFields, String classNameSuffix, String outerQueryAlias, DocumentProjectionData projectionData, Int32 nestingLevel)
   at SD_DTO_RootDerivedElementReadOnlyPersistence.ProduceDocumentProjectorQs(String baseQueryName, String documentNameForOutput, DocumentDefinitionBase document, IGenerator executingGenerator, SourceNavigatorPath lambdaScopePath, String typesNamespace, Int32 numberOfRootTabs, Boolean inlineValueTypeFields, String classNameSuffix, String outerQueryAlias, DocumentProjectionData projectionData, Int32 nestingLevel)
   at SD_DTO_RootDerivedElementReadOnlyPersistence.__ScriptCode()
   at SD.LLBLGen.Pro.GeneratorCore.CodeGenerationEngineBase.EmitOutputToFile[TElement](TElement currentElement, String destinationFilename, Boolean failWhenExistent, Assembly compiledTemplatesAssembly, String templateID, Dictionary`2 parameters, Boolean isPartOfSet, String outputDescription, String dependentUponFilename)
   at SD.LLBLGen.Pro.GeneratorCore.CodeGenerationEngineBase.EmitOutputForElements[TElement](String destinationFolderFormat, String filenameFormat, Boolean failWhenExistent, String templateID, Assembly compiledTemplatesAssembly, Dictionary`2 parameters, ICollection`1 elementsToTraverse, EmitType emitTypeUsed, Func`2 nameProducerFunc, Func`2 fullNameProducerFunc, Func`2 elementTypeNameProducerFunc, Func`2 groupNameProducerFunc, String dependentUponFilenameFormat, Func`3 preFormatFunc)
   at SD.LLBLGen.Pro.GeneratorCore.CodeGenerationEngineBase.EmitOutput(Dictionary`2 parameters, String destinationFolderFormat, String templateID, Assembly compiledTemplatesAssembly, EmitType emitTypeToPerform, String filenameFormat, Boolean failWhenExistent, String dependentUponFilenameFormat, String emptyGroupReplacementString)
   at SD.LLBLGen.Pro.LptParser.DotNetTemplateEngine.Perform(IGenerator executingGenerator, ITask taskDefinition, Dictionary`2 parameters)
   at SD.LLBLGen.Pro.ApplicationCore.CodeGenerationMetaData.Tasks.Task.PerformElement(IGenerator executingGenerator, LogNode parentNode)
   at SD.LLBLGen.Pro.ApplicationCore.CodeGenerationMetaData.Tasks.TaskGroupElement.Perform(IGenerator executingGenerator, LogNode parentNode)
   at SD.LLBLGen.Pro.ApplicationCore.CodeGenerationMetaData.Tasks.TaskGroup.PerformElement(IGenerator executingGenerator, LogNode parentNode)
   at SD.LLBLGen.Pro.ApplicationCore.CodeGenerationMetaData.Tasks.TaskGroupElement.Perform(IGenerator executingGenerator, LogNode parentNode)
   at SD.LLBLGen.Pro.ApplicationCore.CodeGenerationMetaData.Tasks.TaskGroup.PerformElement(IGenerator executingGenerator, LogNode parentNode)
   at SD.LLBLGen.Pro.ApplicationCore.CodeGenerationMetaData.Tasks.TaskGroupElement.Perform(IGenerator executingGenerator, LogNode parentNode)
   at SD.LLBLGen.Pro.GeneratorCore.Generator.RunTasks(String rootNameSpaceToUse, String destinationRootFolder, String groupName)
   at SD.LLBLGen.Pro.GeneratorCore.Generator.Start(CodeGenerationTaskBase codeGenTask, ApplicationConfiguration configurationSettings, Boolean performObsoleteFileCleanup)
   at SD.LLBLGen.Pro.Gui.Classes.GuiController.PerformRunCodeGenerationCycleAction(List`1 codeGenTasks, List`1 vsNetProjectsCreated, List`1 sqlFilesGenerated, Boolean debugBuild, LogNode& tasksResultLog)

Inner exception: <null>

Re-produced. Obviously, something related to the Derived Model.

We'll look into it!

Hmm, that's strange, in the debug build it loads fine. Will try a release build. Oh when generating code! Missed that.

The crash occurs in the QuerySpec query generation, so it fails in all versions which have that so also 5.8.x. 5.5 works because it doesn't have QS queries for derived elements.

Fixed in hotfix builds 5.8.7 and 5.9.3

To work around the bug, add at least 1 field to a derived element nested in another document.

Thanks. 5.9.3 fixed it.