The UE5 C1083 error (Cannot open include file: 'MyHeader.h') occurs when the compiler can’t find a header file. This is often caused by the file being in the wrong directory or the include path not being specified. To fix this, move the header to the correct folder (e.g., Source/MyProject/Public/) or add the include path in Build.cs. This resolves the Unreal Engine 5 header file error.

Fixing UE5 C1083 Error: Cannot Open Include File in C++ Projects

Example Error Message

C1083: Cannot open include file: 'MyActor.h': No such file or directory

Solution

1. Check the file path: Ensure the path in your #include statement is correct.

// If the file is in the same directory
#include "MyActor.h"

// If the file is in a subdirectory
#include "Characters/MyActor.h"

// If the file is in another module
#include "OtherModule/Public/MyActor.h"

2. Update module dependencies: Make sure your module lists any other modules it depends on in the Build.cs file.

// In YourProject.Build.cs
PublicDependencyModuleNames.AddRange(new string[] { 
    "Core", "CoreUObject", "Engine", "InputCore", "OtherModule" 
});

3. Regenerate project files: Right-click on your .uproject file and select “Generate Visual Studio project files”.
4. Check file existence: Verify that the file actually exists in the location you’re trying to include it from.