Okay, I just ran into the following… I did rename the BP just now… and got an error clicking Simulate
Renaming an object (STPoint_C /Game/Maps/ST/SimpleLevel.SimpleLevel:PersistentLevel.STPoint_C_84) on top of an existing object (REINST_STPoint_C_322 /Game/Maps/ST/SimpleLevel.SimpleLevel:PersistentLevel.STPoint2_C_168) is not allowed
Address = 0xaf105bf8 (filename not found) [in C:\WINDOWS\system32\KERNELBASE.dll]
FOutputDeviceWindowsError::Serialize() 0x91fc0d53 + 0 bytes [File=e:\source\unrealengine-4.4.0-release\engine\source\runtime\core\private\windows\windowsplatformoutputdevices.cpp:113] [in E:\Source\UnrealEngine-4.4.0-release\Engine\Binaries\Win64\UE4Editor-Core.dll]
FMsg::Logf__VA() 0x91e8d5aa + 0 bytes [File=e:\source\unrealengine-4.4.0-release\engine\source\runtime\core\private\misc\outputdevice.cpp:547] [in E:\Source\UnrealEngine-4.4.0-release\Engine\Binaries\Win64\UE4Editor-Core.dll]
UObject::Rename() 0x91b0179a + 138 bytes [File=e:\source\unrealengine-4.4.0-release\engine\source\runtime\coreuobject\private\uobject\obj.cpp:87] [in E:\Source\UnrealEngine-4.4.0-release\Engine\Binaries\Win64\UE4Editor-CoreUObject.dll]
AActor::Rename() 0x85c179ed + 18 bytes [File=e:\source\unrealengine-4.4.0-release\engine\source\runtime\engine\private\actor.cpp:703] [in E:\Source\UnrealEngine-4.4.0-release\Engine\Binaries\Win64\UE4Editor-Engine.dll]
UChildActorComponent::ApplyComponentInstanceData() 0x85cc61da + 55 bytes [File=e:\source\unrealengine-4.4.0-release\engine\source\runtime\engine\private\childactorcomponent.cpp:98] [in E:\Source\UnrealEngine-4.4.0-release\Engine\Binaries\Win64\UE4Editor-Engine.dll]
FComponentInstanceDataCache::ApplyToActor() 0x85cc6571 + 31 bytes [File=e:\source\unrealengine-4.4.0-release\engine\source\runtime\engine\private\componentinstancedatacache.cpp:116] [in E:\Source\UnrealEngine-4.4.0-release\Engine\Binaries\Win64\UE4Editor-Engine.dll]
AActor::ExecuteConstruction() 0x85be3373 + 11 bytes [File=e:\source\unrealengine-4.4.0-release\engine\source\runtime\engine\private\actorconstruction.cpp:370] [in E:\Source\UnrealEngine-4.4.0-release\Engine\Binaries\Win64\UE4Editor-Engine.dll]
FBlueprintCompileReinstancer::ReplaceInstancesOfClass() 0x84228e4f + 0 bytes [File=e:\source\unrealengine-4.4.0-release\engine\source\editor\unrealed\private\kismet2\kismetreinstanceutilities.cpp:375] [in E:\Source\UnrealEngine-4.4.0-release\Engine\Binaries\Win64\UE4Editor-UnrealEd.dll]
FBlueprintCompileReinstancer::ReinstanceObjects() 0x84223509 + 0 bytes [File=e:\source\unrealengine-4.4.0-release\engine\source\editor\unrealed\private\kismet2\kismetreinstanceutilities.cpp:168] [in E:\Source\UnrealEngine-4.4.0-release\Engine\Binaries\Win64\UE4Editor-UnrealEd.dll]
FKismetEditorUtilities::CompileBlueprint() 0x8419dfc9 + 0 bytes [File=e:\source\unrealengine-4.4.0-release\engine\source\editor\unrealed\private\kismet2\kismet2.cpp:408] [in E:\Source\UnrealEngine-4.4.0-release\Engine\Binaries\Win64\UE4Editor-UnrealEd.dll]
UEditorEngine::PlayInEditor() 0x83d51699 + 0 bytes [File=e:\source\unrealengine-4.4.0-release\engine\source\editor\unrealed\private\playlevel.cpp:1720] [in E:\Source\UnrealEngine-4.4.0-release\Engine\Binaries\Win64\UE4Editor-UnrealEd.dll]
UEditorEngine::StartQueuedPlayMapRequest() 0x83d68669 + 0 bytes [File=e:\source\unrealengine-4.4.0-release\engine\source\editor\unrealed\private\playlevel.cpp:838] [in E:\Source\UnrealEngine-4.4.0-release\Engine\Binaries\Win64\UE4Editor-UnrealEd.dll]
UEditorEngine::Tick() 0x83ac5178 + 13 bytes [File=e:\source\unrealengine-4.4.0-release\engine\source\editor\unrealed\private\editor.cpp:1101] [in E:\Source\UnrealEngine-4.4.0-release\Engine\Binaries\Win64\UE4Editor-UnrealEd.dll]
UUnrealEdEngine::Tick() 0x83ef56c6 + 0 bytes [File=e:\source\unrealengine-4.4.0-release\engine\source\editor\unrealed\private\unrealedengine.cpp:252] [in E:\Source\UnrealEngine-4.4.0-release\Engine\Binaries\Win64\UE4Editor-UnrealEd.dll]
FEngineLoop::Tick() 0xcab9754e + 0 bytes [File=e:\source\unrealengine-4.4.0-release\engine\source\runtime\launch\private\launchengineloop.cpp:2098] [in E:\Source\UnrealEngine-4.4.0-release\Engine\Binaries\Win64\UE4Editor.exe]
GuardedMain() 0xcab8cc7c + 0 bytes [File=e:\source\unrealengine-4.4.0-release\engine\source\runtime\launch\private\launch.cpp:133] [in E:\Source\UnrealEngine-4.4.0-release\Engine\Binaries\Win64\UE4Editor.exe]
GuardedMainWrapper() 0xcab8ccea + 5 bytes [File=e:\source\unrealengine-4.4.0-release\engine\source\runtime\launch\private\windows\launchwindows.cpp:125] [in E:\Source\UnrealEngine-4.4.0-release\Engine\Binaries\Win64\UE4Editor.exe]
WinMain() 0xcab98ad9 + 17 bytes [File=e:\source\unrealengine-4.4.0-release\engine\source\runtime\launch\private\windows\launchwindows.cpp:201] [in E:\Source\UnrealEngine-4.4.0-release\Engine\Binaries\Win64\UE4Editor.exe]
__tmainCRTStartup() 0xcab99989 + 21 bytes [File=f:\dd\vctools\crt\crtw32\dllstuff\crtexe.c:618] [in E:\Source\UnrealEngine-4.4.0-release\Engine\Binaries\Win64\UE4Editor.exe]
Address = 0xb08e16ad (filename not found) [in C:\WINDOWS\system32\KERNEL32.DLL]
Address = 0xb1a04629 (filename not found) [in C:\WINDOWS\SYSTEM32\ntdll.dll]
Address = 0xb1a04629 (filename not found) [in C:\WINDOWS\SYSTEM32\ntdll.dll]