How to prevent Garbage Collection

[anonymous_user_b03fd4ba]

Hi everyone. I’ve singleton c++ UObject class wich i call in blueprint widget.

.H

private:
	/* Constructor */
	UNetworkManager();

	/* Singleton */
	static UNetworkManager *instance;

public:
	UFUNCTION(BlueprintCallable, Category = "NetworkManager")
	static UNetworkManager *Instance();

.CPP

/* Singleton */
UNetworkManager *UNetworkManager::instance = NULL;

/* Singleton */
UNetworkManager *UNetworkManager::Instance()
{
	if(!instance)
		instance = NewObject<UNetworkManager>();
	return instance;
}

Widget

At first all work fine, but some time after i get an error:

LogScript:Warning: Attempted to access NetworkManager_0 via property CallFunc_Instance_ReturnValue, but NetworkManager_0 is pending kill
    AuthLevelWidget_C /Engine/Transient.UnrealEdEngine_0:GameInstance_0.AuthLevelWidget_C_0
    Function /Game/AuthLevel/AuthLevelWidget.AuthLevelWidget_C:ExecuteUbergraph_AuthLevelWidget:00A6

I think it happens because the Garbage Collector remove the class, but i’m not sure.
How to fix it ?

Hope somebody help me.
Thanks.

[anonymous_user_b03fd4ba]

Add validation in Widget, and now i know: instance do not valid only in Widget Blueprint

IsValid function after some time returned false;

I do not understand what happening :c
[1]:

[anonymous_user_b03fd4ba]

I find an answer
We can using UObject flag to prevent Garbage Collection

instance->AddToRoot();