How to Resolve UE5 C2061 Syntax Error: Identifier Not Found in C++ Projects

Why You’re Seeing This Error

This error occurs when you’re using a type that hasn’t been properly declared or included in your file. The compiler doesn’t recognize the type you’re referring to.

Example Error Message

C2061: syntax error: identifier 'UUserWidget'

Solution

1. Include the necessary header file: Make sure you’ve included the header file that defines the type you’re using.

// Add this at the top of your file
#include "Blueprint/UserWidget.h"

2. Use forward declarations: For class types that you only reference (not inherit from or access members of), you can use forward declarations.

// At the top of your header file, before your class declaration
class UUserWidget;  // Forward declaration

UCLASS()
class MYGAME_API AMyController : public APlayerController
{
    GENERATED_BODY()
    
    UPROPERTY()
    UUserWidget* MyWidget;  // Using the forward-declared type
};

3. Check the module dependencies: Make sure your project’s Build.cs file includes the necessary module dependencies.

// In YourProject.Build.cs
PublicDependencyModuleNames.AddRange(new string[] { 
    "Core", "CoreUObject", "Engine", "InputCore", "UMG" // Add UMG for UserWidget classes
});