Assertion Failed Index >= 0 in Standalone Game

I’m getting the following error ONLY when launching the game in Standalone or from a packaged build.
I’m fairly confident this has to do with something with my array code, but I’m not certain why it works fine inside the editor. You’ll find the chunk of code that I think is causing the problem at the very bottom.

Assertion failed: Index >= 0 [File:d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\coreuobject\public\uobject\UObjectArray.h] [Line: 401] 



UE4Editor_Core!FDebug::AssertFailed() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\core\private\misc\outputdevice.cpp:430]
UE4Editor_CoreUObject!UObject::ProcessContextOpcode() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:1907]
UE4Editor_CoreUObject!UObject::execLetObj() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:1751]
UE4Editor_CoreUObject!UObject::ProcessInternal() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:781]
UE4Editor_CoreUObject!UObject::CallFunction() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:686]
UE4Editor_CoreUObject!UObject::execVirtualFunction() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:2022]
UE4Editor_CoreUObject!UObject::ProcessInternal() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:781]
UE4Editor_CoreUObject!UFunction::Invoke() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\coreuobject\private\uobject\class.cpp:4482]
UE4Editor_CoreUObject!UObject::ProcessEvent() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:1150]
UE4Editor_Engine!AActor::ProcessEvent() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\engine\private\actor.cpp:611]
UE4Editor_Engine!FInputActionHandlerDynamicSignature::Execute() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\engine\classes\components\inputcomponent.h:93]
UE4Editor_Engine!FInputActionUnifiedDelegate::Execute() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\engine\classes\components\inputcomponent.h:189]
UE4Editor_Engine!UPlayerInput::ProcessInputStack() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\engine\private\userinterface\playerinput.cpp:1211]
UE4Editor_Engine!APlayerController::ProcessPlayerInput() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\engine\private\playercontroller.cpp:2310]
UE4Editor_Engine!APlayerController::TickPlayerInput() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\engine\private\playercontroller.cpp:3878]
UE4Editor_Engine!APlayerController::PlayerTick() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\engine\private\playercontroller.cpp:1980]
UE4Editor_Engine!APlayerController::TickActor() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\engine\private\playercontroller.cpp:3954]
UE4Editor_Engine!FActorTickFunction::ExecuteTick() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\engine\private\actor.cpp:110]
UE4Editor_Engine!FTickFunctionTask::DoTask() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\engine\private\ticktaskmanager.cpp:228]
UE4Editor_Engine!TGraphTask<FTickFunctionTask>::ExecuteTask() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\core\public\async\taskgraphinterfaces.h:886]
UE4Editor_Core!FNamedTaskThread::ProcessTasksNamedThread() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\core\private\async\taskgraph.cpp:779]
UE4Editor_Core!FNamedTaskThread::ProcessTasksUntilQuit() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\core\private\async\taskgraph.cpp:526]
UE4Editor_Core!FTaskGraphImplementation::WaitUntilTasksComplete() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\core\private\async\taskgraph.cpp:1534]
UE4Editor_Engine!FTickTaskSequencer::ReleaseTickGroup() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\engine\private\ticktaskmanager.cpp:486]
UE4Editor_Engine!FTickTaskManager::RunTickGroup() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\engine\private\ticktaskmanager.cpp:1373]
UE4Editor_Engine!UWorld::RunTickGroup() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\engine\private\leveltick.cpp:702]
UE4Editor_Engine!UWorld::Tick() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\engine\private\leveltick.cpp:1187]
UE4Editor_Engine!UGameEngine::Tick() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\engine\private\gameengine.cpp:989]
UE4Editor!FEngineLoop::Tick() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\launch\private\launchengineloop.cpp:2643]
UE4Editor!GuardedMain() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\launch\private\launch.cpp:142]
UE4Editor!GuardedMainWrapper() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() [d:\buildfarm\buildmachine_++ue4+release-4.11\engine\source\runtime\launch\private\windows\launchwindows.cpp:200]
UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:264]
kernel32
ntdll

Here’s my array code, if you are curious I printed the count function in the same way I call GetRandomItem and it’s 2 in the case where this appears to be crashing:

UItem* UItemContainer::GetRandomItem()
{
	TArray<UItem*> itemArray;

	this->Items.GenerateValueArray(itemArray);

	return itemArray[FMath::RandRange(0, this->Count() - 1)];
}

Ho ho! I figured it out. It appears that the container object to my array was being digested by the GC.

I fixed it by using:
YourObjectInstance->AddToRoot();