# UE4 4.12.4 crashes on Dedicated Server Mode **URL:** \ **Category:** Programming & Scripting\ **Tags:** unreal-engine\ **Created:** [June 30, 2016, 8:40pm UTC](https://forums.unrealengine.com/t/ue4-4-12-4-crashes-on-dedicated-server-mode/362577 "2016-06-30T20:40:54Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![KAISERVRS](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@KAISERVRS](https://forums.unrealengine.com/u/KAISERVRS)\ **Post date:** [June 30, 2016, 8:40pm UTC](https://forums.unrealengine.com/t/ue4-4-12-4-crashes-on-dedicated-server-mode/362577/1 "2016-06-30T20:40:54Z")
Hey, like the topic says the ue4 engine suddenly starts to crash every time I want to test the game in dedicated server mode. This already happened to me a few days ago - I fixed it with a full build of the game - Now it’s happening again and I cant fix it ☹ Error log of the Engine: > Assertion failed: > Property-\>PropertyFlags & CPF\_Net > [File:D:\Build++UE4+Release-4.12+Compile\Sync\Engine\Source\Runtime\Engine\Private\RepLayout.cpp] > [Line: 2666] > > UE4Editor\_Core!FDebug::AssertFailed() > [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\core\private\misc\outputdevice.cpp:440] > UE4Editor\_Engine!FRepLayout::InitFromObjectClass() > [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\engine\private\replayout.cpp:2668] > UE4Editor\_Engine!UNetDriver::GetObjectClassRepLayout() > [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\engine\private\networkdriver.cpp:3314] > UE4Editor\_Engine!UNetDriver::FindOrCreateRepChangedPropertyTracker() > [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\engine\private\networkdriver.cpp:3298] > UE4Editor\_Engine!AActor::CallPreReplication() > [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\engine\private\actor.cpp:907] > UE4Editor\_Engine!UNetDriver::ServerReplicateActors\_BuildConsiderList() > [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\engine\private\networkdriver.cpp:2444] > UE4Editor\_Engine!UNetDriver::ServerReplicateActors() > [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\engine\private\networkdriver.cpp:2923] > UE4Editor\_Engine!UNetDriver::TickFlush() > [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\engine\private\networkdriver.cpp:294] > UE4Editor\_Engine!TBaseUObjectMethodDelegateInstance\<0,UNetDriver,void > \_\_cdecl(float)\>::ExecuteIfSafe() [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl\_variadics.inl:852] > UE4Editor\_Engine!TBaseMulticastDelegate::Broadcast() > [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\core\public\delegates\delegatesignatureimpl\_variadics.inl:921] > UE4Editor\_Engine!UWorld::Tick() > [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\engine\private\leveltick.cpp:1327] > UE4Editor\_UnrealEd!UEditorEngine::Tick() > [d:\build++ue4+release-4.12+compile\sync\engine\source\editor\unrealed\private\editorengine.cpp:1349] > UE4Editor\_UnrealEd!UUnrealEdEngine::Tick() > [d:\build++ue4+release-4.12+compile\sync\engine\source\editor\unrealed\private\unrealedengine.cpp:368] > UE4Editor!FEngineLoop::Tick() > [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\launchengineloop.cpp:2775] > UE4Editor!GuardedMain() > [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\launch.cpp:148] > UE4Editor!GuardedMainWrapper() > [d:\build++ue4+release-4.12+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:126] > UE4Editor!WinMain() > [d:\build++ue4+release-4.12+compile\sync\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 ---
**Author:** ![KAISERVRS](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@KAISERVRS](https://forums.unrealengine.com/u/KAISERVRS)\ **Post date:** [July 1, 2016, 6:18pm UTC](https://forums.unrealengine.com/t/ue4-4-12-4-crashes-on-dedicated-server-mode/362577/2 "2016-07-01T18:18:45Z")
Bump - Problem is still there 😕 ---
**Author:** ![KAISERVRS](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@KAISERVRS](https://forums.unrealengine.com/u/KAISERVRS)\ **Post date:** [July 1, 2016, 6:25pm UTC](https://forums.unrealengine.com/t/ue4-4-12-4-crashes-on-dedicated-server-mode/362577/3 "2016-07-01T18:25:56Z")
I deleted a map out of my content folder and it’s fixed. Is it possible that an unused map canmake those errors? ---
**Author:** ![KAISERVRS](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@KAISERVRS](https://forums.unrealengine.com/u/KAISERVRS)\ **Post date:** [July 7, 2016, 8:38am UTC](https://forums.unrealengine.com/t/ue4-4-12-4-crashes-on-dedicated-server-mode/362577/4 "2016-07-07T08:38:12Z")
Now after a few days again - UE4 is crashing on In-Editor starts until I delete ALL maps. I downgraded my project to 4.11 again - But I really want to know the problem here? So - BUMP ---
**Author:** ![CriErr](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@CriErr](https://forums.unrealengine.com/u/CriErr)\ **Post date:** [July 27, 2016, 7:53am UTC](https://forums.unrealengine.com/t/ue4-4-12-4-crashes-on-dedicated-server-mode/362577/5 "2016-07-27T07:53:32Z")
Check here, maybe you have something to add to my post. > **[Play in Editor with network crash RepLayout.cpp \[Line: 2666\]](https://forums.unrealengine.com/questions/459750/play-in-editor-with-network-crash-replayoutcpp-lin.html)** > > If project tested in play in editor mode with networking enabled (dedicated server or more than one client) after actor gets spawned to level, project crashes. Spawned Actor has 4 parents with replicated variables in them. Recompile one one the... ---
**Author:** ![Jake1337](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Jake1337](https://forums.unrealengine.com/u/Jake1337)\ **Post date:** [August 2, 2016, 9:45pm UTC](https://forums.unrealengine.com/t/ue4-4-12-4-crashes-on-dedicated-server-mode/362577/6 "2016-08-02T21:45:34Z")
Got similar crashes here with same stack, only for me it happens when I run a multiplayer listen server and client(s) in editor. This has started happening a while ago but has come to the point where it is near impossible to debug a multiplayer game. Have recently upgraded to 4.12 and problem persists… If more info is needed please specify what will be useful ---
**Author:** ![atanknomore](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@atanknomore](https://forums.unrealengine.com/u/atanknomore)\ **Post date:** [August 8, 2016, 2:42am UTC](https://forums.unrealengine.com/t/ue4-4-12-4-crashes-on-dedicated-server-mode/362577/7 "2016-08-08T02:42:28Z")
4.12.5 still having this issue with several projects. Any input from the devs? ---
**Author:** ![CriErr](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@CriErr](https://forums.unrealengine.com/u/CriErr)\ **Post date:** [August 8, 2016, 4:55am UTC](https://forums.unrealengine.com/t/ue4-4-12-4-crashes-on-dedicated-server-mode/362577/8 "2016-08-08T04:55:38Z")
Did you manage to find clear repro? ---
**Author:** ![atanknomore](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@atanknomore](https://forums.unrealengine.com/u/atanknomore)\ **Post date:** [August 8, 2016, 7:37am UTC](https://forums.unrealengine.com/t/ue4-4-12-4-crashes-on-dedicated-server-mode/362577/9 "2016-08-08T07:37:52Z")
No not yet. It’s also quite inconsistent. I get it sometimes, sometimes I don’t.