What It Means & How to Fix It in UE5

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🧠 Why You’re Seeing This Error

This error happens when you use the GENERATED_BODY() (or GENERATED_UCLASS_BODY()) macro inside a header file, but don’t include the required .generated.h file that Unreal Header Tool (UHT) expects at the bottom of the file.

Without this include, the macro expands into code that doesn’t exist yet — and the compiler throws an error.

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💥 Example Error Message

error: expected class name
error: 'GENERATED_BODY': macro used without including generated header

Or:

fatal error: file not found: 'MyClass.generated.h'

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🛠️ What Usually Causes This

❌ You Forgot to Include the .generated.h File

// MyClass.h
#pragma once

#include "CoreMinimal.h"

UCLASS()
class MYGAME_API AMyClass : public AActor
{
    GENERATED_BODY() // ❌ No corresponding .generated.h file included
};

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❌ You Included the .generated.h Too Early

// ❌ Wrong order
#include "MyClass.generated.h"
#include "CoreMinimal.h"

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✅ How to Fix It – Step-by-Step

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✔️ 1. Add the Missing .generated.h Include at the Bottom of the Header File

It must be the last include in the header:

// MyClass.h
#pragma once

#include "CoreMinimal.h"
#include "MyClass.generated.h" // ✅ Must come last

UCLASS()
class MYGAME_API AMyClass : public AActor
{
    GENERATED_BODY()

public:
    AMyClass();
};

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✔️ 2. Make Sure the File Name Matches the Class

If your header is called EnemyCharacter.h, the include should be:

#include "EnemyCharacter.generated.h"

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✔️ 3. Rebuild and Let UHT Generate the Code

Once the include is added:

// Do this:
- Right-click your .uproject → Generate Visual Studio project files
- Rebuild your project

UHT will now generate the missing .generated.h file automatically.

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✅ Summary: How to Fix “Missing Include for GENERATED_BODY Macro” in UE5

Cause	Fix
.generated.h file not included	Add #include "MyClass.generated.h" at the end of the header
Include order is wrong	Ensure .generated.h is the last include in the file
File name mismatch	Use the correct generated include name based on the header file
UHT not triggered	Regenerate project files and rebuild the project