Error with new blank C++ project, add new C++ file

When I create a new blank C++ project,and add new C++ file,‘LandscapeEditorObject‘ as its parent class. It report an error:
“Successfully added class ‘MyLandscapeEditorObject’,however you must recompile the ‘MyProject’ module before it will appear in the Content Browser.Failed to automatically hot reload the ‘MyProject’ module.”

It seems all the classes in the path “Editor/LandscapeEditor/”,that if I choose one as parent class, it will show this error.

I tryed to compile the project mannully, and the error is:

MyLandscapeEditorObject.cpp.obj : error LNK2001: “public: virtual void __cdecl ULandscapeEditorObject::PostEditChangeProperty(struct FPropertyChangedEvent &)” (?PostEditChangeProperty@ULandscapeEditorObject@@UEAAXAEAUFPropertyChangedEvent@@@Z)
2>MyLandscapeEditorObject.gen.cpp.obj : error LNK2001: “public: virtual void __cdecl ULandscapeEditorObject::PostEditChangeProperty(struct FPropertyChangedEvent &)” (?PostEditChangeProperty@ULandscapeEditorObject@@UEAAXAEAUFPropertyChangedEvent@@@Z)
2>F:\Project\GGG\MyProject2\Binaries\Win64\UE4Editor-MyProject2-4984.dll : fatal error LNK1120

Have you declared PostEditChangeProperty as a method in your .h file and not your .cpp?

If you’re not doing anything with this method then remove them from your .h and .cpp, or you can add the method to your .cpp and just call Super::PostEditChangeProperty(…) but that’s a little pointless.

If you are using this method, then you just need to define it in your cpp file (and make sure your namespace is correct: UMyLandscapeEditorObject::PostEditChangeProperty).

Hi,phil_me_up ,thank for response!

There is no call for PostEditChangeProperty.
I did not write anything,just a blank project.
And I create a new c++ file extends to ‘LandscapeEditorObject’ in UE4 editor

MyLandscapeEditorObject.h:

#pragma once

#include “CoreMinimal.h”
#include “LandscapeEditorObject.h”
#include “MyLandscapeEditorObject.generated.h”

/**
*
*/
UCLASS()
class EEEEEEEE_API UMyLandscapeEditorObject : public ULandscapeEditorObject
{
GENERATED_BODY()

};

MyLandscapeEditorObject.cpp:

#include “MyLandscapeEditorObject.h”

.uproject:

{
“FileVersion”: 3,
“EngineAssociation”: “4.21”,
“Category”: “”,
“Description”: “”,
“Modules”: [
{
“Name”: “EEEEEEEE”,
“Type”: “Runtime”,
“LoadingPhase”: “Default”,
“AdditionalDependencies”: [
“LandscapeEditor”
]
}
]
}