4.10.4 - Still getting crashes on level change (Multiplayer)


I think there was an issue recently with level changes causing a crash (UE-27124 perhaps?).

We’ve spent a lot of day trying to nail this down, but we just noticed that 4.10.4 just got released. We have updated, but we’re still seeing crashing behavior when changing levels in a multiplayer environment.

I will provide you with an example project if needed, but I suspect you’ll be able to replicate it as it is currently causing issues with one of your projects.
Repo steps:

  • Download / Install / Create a project from ‘Multiplayer Shootout’ project in learn tab.
  • Open this project
  • Click dropdown next to play button
  • Change number of players to 2
  • Go into advanced settings section at bottom of menu
  • Turn off “auto connect to server” in multiplayer options section at bottom
  • IMPORTANT → Open menu map (MainMenu)
  • Set game to start in a new PIE window
  • Click play in one window (it will load and work fine)
  • On other, search for games. When it finds game, click join.
  • engine will crash.

log is as follows:


Unknown exception - code 00000001 (first/second chance not available)

"Ensure condition failed: !ActorComponent->IsRegistered() || ActorComponent->GetScene() != this [File:D:\BuildFarm\buildmachine_++depot+UE4-Releases+4.10\En

UE4Editor_Core!FDebug::OptionallyLogFormattedEnsureMessageReturningFalse() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\core\private\misc\outputdevice.cpp:385]
UE4Editor_Renderer!FScene::Release() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\renderer\private\rendererscene.cpp:1922]
UE4Editor_Engine!UWorld::FinishDestroy() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\engine\private\world.cpp:522]
UE4Editor_CoreUObject!UObject::ConditionalFinishDestroy() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\coreuobject\private\uobject\obj.cpp:685]
UE4Editor_CoreUObject!StaticAllocateObject() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1979]
UE4Editor_CoreUObject!StaticConstructObject_Internal() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:2610]
UE4Editor_CoreUObject!StaticDuplicateObjectEx() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1584]
UE4Editor_CoreUObject!StaticDuplicateObject() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1553]
UE4Editor_UnrealEd!UEditorEngine::CreatePIEWorldByDuplication() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\editor\unrealed\private\playlevel.cpp:3455]
UE4Editor_Engine!UEngine::LoadMap() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\engine\private\unrealengine.cpp:9457]
UE4Editor_Engine!UEngine::TickWorldTravel() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\engine\private\unrealengine.cpp:8896]
UE4Editor_UnrealEd!UEditorEngine::Tick() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\editor\unrealed\private\editorengine.cpp:1285]
UE4Editor_UnrealEd!UUnrealEdEngine::Tick() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\editor\unrealed\private\unrealedengine.cpp:361]
UE4Editor!FEngineLoop::Tick() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\launch\private\launchengineloop.cpp:2427]
UE4Editor!GuardedMain() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\launch\private\launch.cpp:142]
UE4Editor!GuardedMainWrapper() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.10\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]

I can replicate this in my projects and Epic multiplayer one.

If you could confirm this bug as soon as possible, so I know it’s nothing our end, I would appreciate it. I’m currently teaching multiplayer within UE4 in Epic Games Center at Staffs Uni, so it’s breaking a lot of things we’re doing right now.

Many thanks

Hi Agent,

This appears to be a different crash, one that is not new to 4.10.4 (though it had a different call stack in 4.10.3). I’ve entered a report for crash as UE-27242, and I’ll update you here when I see any change in its status. Thanks for report!

For now, I’d recommend not using 4.10.1 or beyond to test networking. While everything will still work in a packaged or launched game (which would be what I would normally recommend using rather than PIE), but in 4.10.1 and beyond, it’s not possible to connect two instances of a game using Steam on same computer. You can grab 4.10.0 from GitHub, which I know works as expected. I believe 4.10.1 is where this bug showed up.

Thanks for reply .
For reference, and hopefully to help anyone else:

4.9.2 – using create session node, Lan = true, Connections = 2

Editor preferences → Network → Auto Connect to server = True

Result = You will be able to host game on ‘server’ window and ‘client’ will be able to connect successfully. If you try to host from client window, it will fail (expected I assume).

Editor preferences → Network → Auto Connect to server = False

Result = You will be able to host game in one of windows, but other one will not be able to connect. You will get a dialog box pop up in bottom right warning of an error:

Warning TravelFailure: LoadMapFailure, Reason for Failure: ‘Failed to load package ‘/Game/Levels/UEDPIE_2_GameLevel’’. Shutting down PIE

You will be gracefully returned to editor.

4.10.4 – using same settings as above:

Auto connect = true. You will be able to connect to server fine, even if it is running a different map. client will correctly load level. This is same as 4.9.2

Auto connect = false. You will be able to host game, but as soon as client tries to connect, editor will crash.

If you compile game, you will be able to test that game works in a real server / client relationship. You will not get a crash when it is packaged, even with 4.10.4.

This crash in 4.10 (UE-27242), along with UE-27124 bug from 4.10.3 meant this was really difficult to troubleshoot, so I hope you’ll understand why I thought this could have been a regression. action of joining server means that both UE-27124 was present (open in Blueprint in this case), and UE-27242 in form of trying to test our game in a server / client relationship inside of editor (and not using auto-connect)

Thanks for prompt reply. It’s very problematic for us to build and deploy another version across our network separate to launcher, but that’s another issue entirely.


I am crashing but my code is not a multi-player. It happens when:

  • running UE v 4.10.4
  • single player (not multi-player)
  • crash when switching levels
  • crash also when I try to open level (map) in editor (without playing game)
  • OSX/Yosemite
  • everything was running okay until 4.10.2

This is crash log:


Generating report for minidump

Application version 4.10.4-0
… built from changelist 2872498

OS version
Running 1 x64 processors
Exception was " SEGV_MAPERR at 0x1d8"

Source context from “”

ADirectionalLight::PostLoad() Address = 0x10c5787a8 (filename not found) [in UE4Editor-Engine.dylib]
UObject::ConditionalPostLoad() Address = 0x10b2e7bad (filename not found) [in UE4Editor-CoreUObject.dylib]
EndLoad() Address = 0x10b456c8f (filename not found) [in UE4Editor-CoreUObject.dylib]
LoadPackageInternal(UPackage*, wchar_t const*, unsigned int, FLinkerLoad*) Address = 0x10b453e61 (filename not found) [in UE4Editor-CoreUObject.dylib]
UEngine::LoadMap(FWorldContext&, FURL, UPendingNetGame*, FString&) Address = 0x10cb288b6 (filename not found) [in UE4Editor-Engine.dylib]
UEngine::Browse(FWorldContext&, FURL, FString&) Address = 0x10cb21e37 (filename not found) [in UE4Editor-Engine.dylib]
UEngine::TickWorldTravel(FWorldContext&, float) Address = 0x10cb23ef5 (filename not found) [in UE4Editor-Engine.dylib]
UEditorEngine::Tick(float, bool) Address = 0x111f6b0a8 (filename not found) [in UE4Editor-UnrealEd.dylib]
UUnrealEdEngine::Tick(float, bool) Address = 0x112621d1c (filename not found) [in UE4Editor-UnrealEd.dylib]
FEngineLoop::Tick() Address = 0x10a6ea602 (filename not found) [in UE4Editor]
GuardedMain(wchar_t const*) Address = 0x10a6f1fa3 (filename not found) [in UE4Editor]
-[UE4AppDelegate runGameThread:] Address = 0x10a700e83 (filename not found) [in UE4Editor]
-[FCocoaGameThread main] Address = 0x10a88aa3b (filename not found) [in UE4Editor-Core.dylib]
Unknown() Address = 0x7fff94de0e92 (filename not found) [in Foundation]
_pthread_body Address = 0x7fff8e58105a (filename not found) [in libsystem_pthread.dylib]
_pthread_body Address = 0x7fff8e580fd7 (filename not found) [in libsystem_pthread.dylib]
thread_start Address = 0x7fff8e57e3ed (filename not found) [in libsystem_pthread.dylib]

529 loaded modules
UE4Editor ( 0x0000000009470000 0xfffa6001 /Users/Shared/UnrealEngine/4.10/Engine/Binaries/Mac/UE4Editor.app/Contents/MacOS
UE4Editor-Core.dylib ( 0x00000000094f0000 0xff9a8001 /Users/Shared/UnrealEngine/4.10/Engine/Binaries/Mac/UE4Editor.app/Contents/MacOS/
UE4Editor-CoreUObject.dylib ( 0x0000000009f48000 0xffc4d001 /Users/Shared/UnrealEngine/4.10/Engine/Binaries/Mac/UE4Editor.app/Contents/MacOS/
UE4Editor-Engine.dylib ( 0x000000000a4b5000 0xfcca3001 /Users/Shared/UnrealEngine/4.10/Engine/Binaries/Mac/UE4Editor.app/Contents/MacOS/
UE4Editor-InputCore.dylib ( 0x000000000f743000 0xfff6a001 /Users/Shared/UnrealEngine/4.10/Engine/Binaries/Mac/UE4Editor.app/Contents/MacOS/
UE4Editor-MediaAssets.dylib ( 0x000000000f7fd000 0xfffd3001 /Users/Shared/UnrealEngine/4.10/Engine/Binaries/Mac/UE4Editor.app/Contents/MacOS/
UE4Editor-MoviePlayer.dylib ( 0x000000000f861000 0xfffdb001 /Users/Shared/UnrealEngine/4.10/Engine/Binaries/Mac/UE4Editor.app/Contents/MacOS/
UE4Editor-Networking.dylib ( 0x000000000f8b9000 0xffff4001 /Users/Shared/UnrealEngine/4.10/Engine/Binaries/Mac/UE4Editor.app/Contents/MacOS/
UE4Editor-PakFile.dylib ( 0x000000000f8cf000 0xfffd1001 /Users/Shared/UnrealEngine/4.10/Engine/Binaries/Mac/UE4Editor.app/Contents/MacOS/
UE4Editor-Projects.dylib ( 0x000000000f924000 0xfffae001 /Users/Shared/UnrealEngine/4.10/Engine/Binaries/Mac/UE4Editor.app/Contents/MacOS/
UE4Editor-RenderCore.dylib ( 0x000000000f99e000 0xfffbe001 /Users/Shared/UnrealEngine/4.10/Engine/Binaries/Mac/UE4Editor.app/Contents/MacOS/
UE4Editor-RHI.dylib ( 0x000000000fa12000 0xfffa3001 /Users/Shared/UnrealEngine/4.10/Engine/Binaries/Mac/UE4Editor.app/Contents/MacOS/
UE4Editor-SandboxFile.dylib ( 0x000000000fac0000 0xfffed001 /Users/Shared/UnrealEngine/4.10/Engine/Binaries/Mac/UE4Editor.app/Contents/MacOS/
UE4Editor-Serialization.dylib ( 0x000000000fae6000 0xfffc3001 /Users/Shared/UnrealEngine/4.10/Engine/Binaries/Mac/UE4Editor.app/Contents/MacOS/
UE4Editor-ShaderCore.dylib ( 0x000000000fb5d000 0xfff51001 /Users/Shared/UnrealEngine/4.10/Engine/Binaries/Mac/UE4Editor.app/Contents/MacOS/
(etc etc)

Hi pcerioli,

This appears to be a different crash than that of original poster. Please create a new post in Bug Reports section and we’ll get someone to look into it. Be sure to include this same information as well as your zipped project logs. Thanks!