Description

Overriding a BlueprintNativeEvent function with a const reference parameter in blueprints causes the project to fail to package if the blueprint is nativized.

Note:
This only occurs if the function has a return value. If the function returns void the project will still compile successfully.

Regression:
No - behavior also occurs in 4.17.2 (CL 2658906)

Steps to Reproduce
  1. Open UE4 Editor (any project)
  2. Add code to project based on actor (MyActor)
  3. Add the following to MyActor.h:
    UFUNCTION(BlueprintNativeEvent, Category = test)
    		bool TestFunc(const float& Rando);
    	virtual bool TestFunc_Implementation(const float& Rando);
    
  4. Add the following to MyActor.cpp:
    bool AMyActor::TestFunc_Implementation(const float& Rando)
    {
    	return true;
    }
    
  5. Compile
  6. Create a blueprint based on MyActor (MyActorBP)
  7. In the MyBlueprint tab, hover over the dark gray Functions bar and open Override dropdown
  8. Select TestFunc to create override for it
  9. Open Class Settings and check the box for Nativize
  10. In Project Settings, Set Nativization Method to Exclusive and add MyActorBP to the list of blueprints to nativize
  11. File->Package Project->Windows->Windows(64-bit)

Result:
Package process fails with provided output

Expected:
Project is packaged for

Callstack
UATHelper: Packaging (Windows (64-bit)): Running AutomationTool...
UATHelper: Packaging (Windows (64-bit)): Parsing command line: -ScriptsForProject="D:/Projects/UnrealProjects/CharacterNameArray 4.18/CharacterNameArray.uproject" BuildCookRun -nocompile -nocompileeditor -installed -nop4 -project="D:/Projects/UnrealProjects/CharacterNameArray 4.18/CharacterNameArray.uproject" -cook -stage -archive -archivedirectory="D:/Proje
cts/UnrealProjects/CharacterNameArray 4.18" -package -clientconfig=Development -ue4exe=UE4Editor-Cmd.exe -pak -prereqs -nodebuginfo -targetplatform=Win64 -build -utf8output
UATHelper: Packaging (Windows (64-bit)): Setting up ProjectParams for D:\Projects\UnrealProjects\CharacterNameArray 4.18\CharacterNameArray.uproject
UATHelper: Packaging (Windows (64-bit)): ********** BUILD COMMAND STARTED **********
UATHelper: Packaging (Windows (64-bit)): No build products were made
UATHelper: Packaging (Windows (64-bit)): ********** BUILD COMMAND COMPLETED **********
UATHelper: Packaging (Windows (64-bit)): ********** COOK COMMAND STARTED **********
UATHelper: Packaging (Windows (64-bit)): Running UE4Editor Cook for project D:\Projects\UnrealProjects\CharacterNameArray 4.18\CharacterNameArray.uproject
UATHelper: Packaging (Windows (64-bit)): Commandlet log file is D:\Epic Games\UE_4.18\Engine\Programs\AutomationTool\Saved\Cook-2017.11.17-14.59.17.txt
UATHelper: Packaging (Windows (64-bit)): Running: D:\Epic Games\UE_4.18\Engine\Binaries\Win64\UE4Editor-Cmd.exe "D:\Projects\UnrealProjects\CharacterNameArray 4.18\CharacterNameArray.uproject" -run=Cook  -NoLogTimes -TargetPlatform=WindowsNoEditor -fileopenlog -unversioned -abslog="D:\Epic Games\UE_4.18\Engine\Programs\AutomationTool\Saved\Cook-2017.11.17-14
.59.17.txt" -stdout -CrashForUAT -unattended  -UTF8Output
UATHelper: Packaging (Windows (64-bit)):   LogInit: Display: Running engine for game: CharacterNameArray
UATHelper: Packaging (Windows (64-bit)):   LogInit: Display: RandInit(-1914398660) SRandInit(-1914398660).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Warning: Module file ../../../../../Projects/UnrealProjects/CharacterNameArray 4.18/Binaries/Win64/UE4Editor-CharacterNameArray-3230.dll is missing. This is likely a stale module that must be recompiled.
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/2D/Paper2D/Binaries/Win64/UE4Editor-Paper2D.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/2D/Paper2D/Binaries/Win64/UE4Editor-Paper2DEditor.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/2D/Paper2D/Binaries/Win64/UE4Editor-PaperSpriteSheetImporter.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/2D/Paper2D/Binaries/Win64/UE4Editor-PaperTiledImporter.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/2D/Paper2D/Binaries/Win64/UE4Editor-SmartSnapping.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Blendables/LightPropagationVolume/Binaries/Win64/UE4Editor-LightPropagationVolumeRuntime.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Blendables/LightPropagationVolume/Binaries/Win64/UE4Editor-LightPropagationVolumeEditor.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Developer/GitSourceControl/Binaries/Win64/UE4Editor-GitSourceControl.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Developer/PerforceSourceControl/Binaries/Win64/UE4Editor-PerforceSourceControl.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Developer/SubversionSourceControl/Binaries/Win64/UE4Editor-SubversionSourceControl.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Developer/UObjectPlugin/Binaries/Win64/UE4Editor-UObjectPlugin.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Developer/VisualStudioCodeSourceCodeAccess/Binaries/Win64/UE4Editor-VisualStudioCodeSourceCodeAccess.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Developer/VisualStudioSourceCodeAccess/Binaries/Win64/UE4Editor-VisualStudioSourceCodeAccess.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Editor/AssetManagerEditor/Binaries/Win64/UE4Editor-AssetManagerEditor.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Editor/AudioCapture/Binaries/Win64/UE4Editor-AudioCapture.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Editor/FacialAnimation/Binaries/Win64/UE4Editor-FacialAnimation.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Editor/FacialAnimation/Binaries/Win64/UE4Editor-FacialAnimationEditor.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Editor/GameplayTagsEditor/Binaries/Win64/UE4Editor-GameplayTagsEditor.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Editor/MobileLauncherProfileWizard/Binaries/Win64/UE4Editor-MobileLauncherProfileWizard.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Editor/PluginBrowser/Binaries/Win64/UE4Editor-PluginBrowser.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Editor/SpeedTreeImporter/Binaries/Win64/UE4Editor-SpeedTreeImporter.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Experimental/AlembicImporter/Binaries/Win64/UE4Editor-AlembicImporter.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Experimental/AlembicImporter/Binaries/Win64/UE4Editor-AlembicLibrary.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Experimental/CharacterAI/Binaries/Win64/UE4Editor-CharacterAI.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Experimental/HTML5Networking/Binaries/Win64/UE4Editor-HTML5Networking.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Media/AndroidMedia/Binaries/Win64/UE4Editor-AndroidMediaEditor.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Media/AndroidMedia/Binaries/Win64/UE4Editor-AndroidMediaFactory.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Media/AvfMedia/Binaries/Win64/UE4Editor-AvfMediaEditor.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Media/AvfMedia/Binaries/Win64/UE4Editor-AvfMediaFactory.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Media/AvfMedia/Binaries/Win64/UE4Editor-AvfMediaFactory.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Media/ImgMedia/Binaries/Win64/UE4Editor-ImgMedia.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Media/ImgMedia/Binaries/Win64/UE4Editor-ImgMediaEditor.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Media/ImgMedia/Binaries/Win64/UE4Editor-ImgMediaFactory.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Media/ImgMedia/Binaries/Win64/UE4Editor-ImgMediaFactory.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Media/ImgMedia/Binaries/Win64/UE4Editor-OpenExrWrapper.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Media/MediaCompositing/Binaries/Win64/UE4Editor-MediaCompositing.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Media/MediaCompositing/Binaries/Win64/UE4Editor-MediaCompositingEditor.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Media/MediaPlayerEditor/Binaries/Win64/UE4Editor-MediaPlayerEditor.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Media/WmfMedia/Binaries/Win64/UE4Editor-WmfMedia.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Media/WmfMedia/Binaries/Win64/UE4Editor-WmfMediaEditor.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Media/WmfMedia/Binaries/Win64/UE4Editor-WmfMediaFactory.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Media/WmfMedia/Binaries/Win64/UE4Editor-WmfMediaFactory.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Messaging/TcpMessaging/Binaries/Win64/UE4Editor-TcpMessaging.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Messaging/UdpMessaging/Binaries/Win64/UE4Editor-UdpMessaging.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/MovieScene/ActorSequence/Binaries/Win64/UE4Editor-ActorSequence.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/MovieScene/LevelSequenceEditor/Binaries/Win64/UE4Editor-LevelSequenceEditor.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/MovieScene/MatineeToLevelSequence/Binaries/Win64/UE4Editor-MatineeToLevelSequence.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Online/OnlineSubsystem/Binaries/Win64/UE4Editor-OnlineSubsystem.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Online/OnlineSubsystemNull/Binaries/Win64/UE4Editor-OnlineSubsystemNull.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Online/OnlineSubsystemUtils/Binaries/Win64/UE4Editor-OnlineSubsystemUtils.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Online/OnlineSubsystemUtils/Binaries/Win64/UE4Editor-OnlineBlueprintSupport.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/AndroidDeviceProfileSelector/Binaries/Win64/UE4Editor-AndroidDeviceProfileSelector.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/AndroidPermission/Binaries/Win64/UE4Editor-AndroidPermission.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/AppleARKit/Binaries/Win64/UE4Editor-AppleARKit.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/ArchVisCharacter/Binaries/Win64/UE4Editor-ArchVisCharacter.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/CableComponent/Binaries/Win64/UE4Editor-CableComponent.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/CustomMeshComponent/Binaries/Win64/UE4Editor-CustomMeshComponent.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/ExampleDeviceProfileSelector/Binaries/Win64/UE4Editor-ExampleDeviceProfileSelector.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/ImmediatePhysics/Binaries/Win64/UE4Editor-ImmediatePhysics.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/ImmediatePhysics/Binaries/Win64/UE4Editor-ImmediatePhysicsEditor.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/LocationServicesBPLibrary/Binaries/Win64/UE4Editor-LocationServicesBPLibrary.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/MobilePatchingUtils/Binaries/Win64/UE4Editor-MobilePatchingUtils.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/Oculus/OculusVR/Binaries/Win64/UE4Editor-OculusHMD.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/Oculus/OculusVR/Binaries/Win64/UE4Editor-OculusInput.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/Oculus/OculusVR/Binaries/Win64/UE4Editor-OculusEditor.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/PhysXVehicles/Binaries/Win64/UE4Editor-PhysXVehicles.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/PhysXVehicles/Binaries/Win64/UE4Editor-PhysXVehiclesEditor.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/ProceduralMeshComponent/Binaries/Win64/UE4Editor-ProceduralMeshComponent.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/ProceduralMeshComponent/Binaries/Win64/UE4Editor-ProceduralMeshComponentEditor.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/RuntimePhysXCooking/Binaries/Win64/UE4Editor-RuntimePhysXCooking.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/Steam/SteamVR/Binaries/Win64/UE4Editor-SteamVR.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/Steam/SteamVR/Binaries/Win64/UE4Editor-SteamVRController.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogModuleManager: Display: Found up-to-date module file ../../../Engine/Plugins/Runtime/WindowsMoviePlayer/Binaries/Win64/UE4Editor-WindowsMoviePlayer.dll (API version 3709383).
UATHelper: Packaging (Windows (64-bit)):   LogInit: Warning: Incompatible or missing module: UE4Editor-CharacterNameArray.dll
UATHelper: Packaging (Windows (64-bit)): Took 2.378s to run UE4Editor-Cmd.exe, ExitCode=1
UATHelper: Packaging (Windows (64-bit)): Cook failed. Deleting cooked data.
UATHelper: Packaging (Windows (64-bit)): ERROR: Cook failed.
UATHelper: Packaging (Windows (64-bit)):        (see C:\Users\doug.wilson\AppData\Roaming\Unreal Engine\AutomationTool\Logs\D+Epic+Games+UE_4.18\UAT_Log.txt for full exception trace)
UATHelper: Packaging (Windows (64-bit)): AutomationTool exiting with ExitCode=25 (Error_UnknownCookFailure)
UATHelper: Packaging (Windows (64-bit)): BUILD FAILED
PackagingResults: Error: Unknown Cook Failure

Have Comments or More Details?

There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-52528 in the post.

2
Login to Vote

Fixed
ComponentUE - Gameplay
Affects Versions4.17.24.18.1
Target Fix4.19
Fix Commit3783678
Main Commit3804136
Release Commit3813083
CreatedNov 17, 2017
ResolvedDec 1, 2017
UpdatedApr 27, 2018