Engine error Z_Construct_UClass_UUserWidget_NoRegister()

Im using unreal 4.8 and I tried to use UserWidget class to load widget blueprint.
I thought this might be an engine error, but not sure.

I added a “UMG” module reference in uproject file but I
got this error : Could not find extern declaration for cross module reference Z_Construct_UClass_UUserWidget_NoRegister(), please help

here is my code

#include "Object.h"
#include "Runtime/UMG/Public/Blueprint/UserWidget.h"
#include "MainMenuContainer.generated.h"
/**
 * 
 */
UCLASS()
class PROJECTTAP_API AMainMenuContainer : public AActor
{
	GENERATED_BODY()
	
public:

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Menu)
		UUserWidget* mainMenuPlacable;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Menu)
		UUserWidget* levelSelectPlacable;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Menu)
		UUserWidget* optionsPlacable;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Menu)
		UUserWidget* creditsPlacable;
};

Did you add this to PrivateDependencyModuleNames or PublicDependencyModuleNames?
I added it to PublicDependencyModuleNames and it works for me.

Not having it anywhere or having it listed in the PrivateDependencyModuleNames one gave me the same error that you had