HCProduct_Tirsova/UE5_BP_to_CPP_Packaging_Guide.md

UE5 Blueprint-to-C++ Project Conversion & Packaging Fix Guide

Problem

When you copy an Unreal Engine 5 Blueprint-only project to a new machine, "Package Project" does nothing -- no error in the UI, no output. The log shows:

LogProjectPackagingSettings: UProjectPackagingSettings FindBestTargetInfo for '' resulted in null FTargetInfo*.
Listing targets that were searched:
  End of target list.

This happens because:

1. The project has no Source/ directory (BP-only projects auto-generate source in Intermediate/Source/ during packaging)
2. Stale configs from the original machine override local settings
3. The editor can't discover build targets without compiled .target metadata files

Step-by-Step Fix

1. Add Modules to .uproject

The .uproject file MUST declare a Modules section. Without it, the editor won't look for .target files in Binaries/ and the target list will always be empty.

Add this before the "Plugins" array:

{
    "FileVersion": 3,
    "EngineAssociation": "5.7",
    "Modules": [
        {
            "Name": "YourProjectName",
            "Type": "Runtime",
            "LoadingPhase": "Default"
        }
    ],
    "Plugins": [
        ...
    ]
}

Critical: Without this section, even if .target files exist in Binaries/, the editor's FindBestTargetInfo will return an empty target list.

2. Create Source/ Directory

Create the following structure at the project root:

Source/
    YourProjectName.Target.cs          (Game target)
    YourProjectNameEditor.Target.cs    (Editor target)
    YourProjectName/
        YourProjectName.Build.cs       (Module build rules)
        YourProjectName.cpp            (Module implementation)

YourProjectName.Target.cs:

using UnrealBuildTool;

public class YourProjectNameTarget : TargetRules
{
    public YourProjectNameTarget(TargetInfo Target) : base(Target)
    {
        DefaultBuildSettings = BuildSettingsVersion.Latest;
        IncludeOrderVersion = EngineIncludeOrderVersion.Latest;
        Type = TargetType.Game;
        ExtraModuleNames.Add("YourProjectName");
    }
}

YourProjectNameEditor.Target.cs:

using UnrealBuildTool;

public class YourProjectNameEditorTarget : TargetRules
{
    public YourProjectNameEditorTarget(TargetInfo Target) : base(Target)
    {
        DefaultBuildSettings = BuildSettingsVersion.Latest;
        IncludeOrderVersion = EngineIncludeOrderVersion.Latest;
        Type = TargetType.Editor;
        ExtraModuleNames.Add("YourProjectName");
    }
}

YourProjectName/YourProjectName.Build.cs:

using UnrealBuildTool;

public class YourProjectName : ModuleRules
{
    public YourProjectName(ReadOnlyTargetRules Target) : base(Target)
    {
        PCHUsage = PCHUsageMode.UseExplicitOrSharedPCHs;
        PrivateDependencyModuleNames.Add("Core");
    }
}

YourProjectName/YourProjectName.cpp:

#include "CoreTypes.h"
#include "Modules/ModuleManager.h"

IMPLEMENT_PRIMARY_GAME_MODULE(FDefaultModuleImpl, YourProjectName, "YourProjectName");

3. Build Both Targets from Command Line

Close the editor, then build from terminal:

:: Build Editor target (needed to open the project)
"C:\Program Files\Epic Games\UE_5.7\Engine\Build\BatchFiles\Build.bat" YourProjectNameEditor Win64 Development "C:\Path\To\YourProject.uproject" -WaitMutex

:: Build Game target (needed for packaging -- THIS IS THE ONE PEOPLE FORGET)
"C:\Program Files\Epic Games\UE_5.7\Engine\Build\BatchFiles\Build.bat" YourProjectName Win64 Shipping "C:\Path\To\YourProject.uproject" -WaitMutex

Critical: You must build BOTH targets. The Editor build creates Simulore_TirsovaEditor.target, and the Game build creates Simulore_Tirsova-Win64-Shipping.target. The packaging system only looks for Game-type targets. If you only build the Editor target, the target list will still be empty.

4. Clean Stale Data from Copied Project

When a project is copied from another machine, these directories contain stale/incompatible data:

Directory	Safe to delete	Regenerated by
Intermediate/	Yes	Editor on startup
Binaries/	Yes	Build step above
DerivedDataCache/	Yes	Editor on startup
Saved/StagedBuilds/	Yes	Packaging process
Saved/Cooked/	Yes	Cooking process
Saved/Crashes/	Yes	Not regenerated (just old logs)
Saved/Temp/	Yes	Editor on startup

Never delete: Config/, Content/, Source/, .uproject, Saved/Config/ (fix it instead)

5. Fix Hardcoded Paths (THE SILENT KILLER)

Copied projects contain paths from the original machine in multiple locations. Check ALL of these:

5a. Config/DefaultGame.ini

[/Script/UnrealEd.ProjectPackagingSettings]
BuildTarget=YourProjectName
StagingDirectory=(Path="")   ; <-- was hardcoded to other user's Desktop

5b. Saved/Config/WindowsEditor/Game.ini (HIGHEST PRIORITY -- overrides DefaultGame.ini!)

This is the one that actually matters for packaging. The editor reads this file, not DefaultGame.ini:

[/Script/DeveloperToolSettings.PlatformsMenuSettings]
StagingDirectory=(Path="")              ; <-- fix this
CookBuildTarget=YourProjectName         ; <-- was empty
PackageBuildTarget=YourProjectName      ; <-- was empty (ROOT CAUSE of "no targets")

This was the hardest bug to find. DefaultGame.ini has BuildTarget=YourProjectName but the editor actually reads PackageBuildTarget from Saved/Config/WindowsEditor/Game.ini, which has higher priority. If this is empty, the editor passes an empty string to FindBestTargetInfo.

5c. Saved/Config/WindowsEditor/EditorPerProjectUserSettings.ini

Search for and fix any paths referencing other machines:

SwarmIntermediateFolder=               ; <-- was C:/Users/OtherUser/...
LastExecutedLaunchDevice=              ; <-- was Windows@OTHER-PC
LastExecutedLaunchName=                ; <-- was OTHER-PC

Quick way to find all stale paths:

grep -rn "C:/Users/" Config/ Saved/Config/ --include="*.ini" | grep -v "prime"

Replace prime with the current username.

UE5 Config Priority System

Understanding this prevents hours of debugging:

Priority	Source	Hex
1 (lowest)	Constructor defaults	0x00
2	Scalability (BaseScalability.ini tiers)	0x01
3	GameUserSettings (in-game quality menu)	0x02
4	ProjectSettings ([/Script/Engine.RendererSettings])	0x03
5	[SystemSettings] and [ConsoleVariables] in DefaultEngine.ini	0x04
6	Device Profiles	0x05
7	Standalone ConsoleVariables.ini (NOT loaded in Shipping!)	0x06
8	Command line	0x07
9	C++ code Set()	0x08
10 (highest)	In-game console (~)	0x09

Where to put rendering overrides:

• [/Script/Engine.RendererSettings] -- Project-level feature toggles (Lumen on/off, RayTracing on/off, VSM on/off). These affect shader compilation.
• [SystemSettings] -- Runtime quality overrides that must survive scalability and device profile changes. Use this for forced quality settings in packaged builds.
• [ConsoleVariables] -- Same priority as SystemSettings. Good for non-rendering cvars (shader pipeline cache, etc).
• DefaultGameUserSettings.ini [ScalabilityGroups] -- Default scalability levels for first-time users. Gets overridden by hardware auto-detect on first run.

Scalability override gotcha:

If you set sg.ShadowQuality=3 in [ScalabilityGroups] AND r.Shadow.MaxResolution=512 in [SystemSettings], the scalability system will apply its shadow preset values first, then [SystemSettings] overrides specific cvars. Your individual settings win because they have higher priority.

However: Device Profiles (priority 0x05) can override [SystemSettings] (priority 0x04). If you see cvars being overridden, check Saved/Config/WindowsEditor/ for device profile configs. The WindowsEditor device profile commonly overrides shadow and scalability settings.

Packaging from Command Line (Bypass Editor UI)

If the editor UI still refuses to package, use RunUAT directly:

"C:\Program Files\Epic Games\UE_5.7\Engine\Build\BatchFiles\RunUAT.bat" BuildCookRun ^
    -project="C:\Path\To\YourProject.uproject" ^
    -platform=Win64 ^
    -clientconfig=Shipping ^
    -cook -build -stage -package -pak ^
    -prereqs -compressed ^
    -target=YourProjectName ^
    -unrealexe="C:\Program Files\Epic Games\UE_5.7\Engine\Binaries\Win64\UnrealEditor-Cmd.exe"

This bypasses the editor's target discovery entirely and invokes UnrealBuildTool + cooker directly.

Checklist Summary

When transferring a BP-only UE5 project to a new machine:

• Add "Modules" section to .uproject
• Create Source/ with Target.cs, Build.cs, and .cpp files
• Build Editor target from command line
• Build Game target (Shipping) from command line
• Delete Intermediate/, Binaries/ (before building), DerivedDataCache/, Saved/StagedBuilds/, Saved/Cooked/
• Fix Config/DefaultGame.ini -- BuildTarget, StagingDirectory
• Fix Saved/Config/WindowsEditor/Game.ini -- PackageBuildTarget, CookBuildTarget, StagingDirectory
• Fix Saved/Config/WindowsEditor/EditorPerProjectUserSettings.ini -- remove other machine's paths
• Grep all .ini files for hardcoded paths from other machines
• Open editor, verify Platforms > Windows > Package Project works