Networked game crashing on play

My networked game has started crashing. It still runs with 1 player. Anyone know what this means?

Summary info:

UE4Editor_Core!FDebug::AssertFailed() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\private\misc\outputdevice.cpp:421]
UE4Editor_ChatSystem_313!TArray::Find() [c:\program files (x86)\epic games\4.13\engine\source\runtime\core\public\containers\array.h:1021]
UE4Editor_ChatSystem_313!TArray::AddUniqueImpl() [c:\program files (x86)\epic games\4.13\engine\source\runtime\core\public\containers\array.h:1979]
UE4Editor_ChatSystem_313!AChatSystemCharacter::GetLifetimeReplicatedProps() [c:\users\reube\documents\unreal projects\chatsystem\source\chatsystem\chatsystemcharacter.cpp:251]
UE4Editor_Engine!FRepLayout::InitFromObjectClass() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\engine\private\replayout.cpp:2925]
UE4Editor_Engine!UNetDriver::GetObjectClassRepLayout() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\engine\private\networkdriver.cpp:3303]
UE4Editor_Engine!UNetDriver::FindOrCreateRepChangedPropertyTracker() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\engine\private\networkdriver.cpp:3287]
UE4Editor_Engine!AActor::CallPreReplication() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\engine\private\actor.cpp:924]
UE4Editor_Engine!UNetDriver::ServerReplicateActors_BuildConsiderList() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\engine\private\networkdriver.cpp:2435]
UE4Editor_Engine!UNetDriver::ServerReplicateActors() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\engine\private\networkdriver.cpp:2906]
UE4Editor_Engine!UNetDriver::TickFlush() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\engine\private\networkdriver.cpp:304]
UE4Editor_Engine!TBaseUObjectMethodDelegateInstance<0,UNetDriver,void __cdecl(float)>::ExecuteIfSafe() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:848]
UE4Editor_Engine!TBaseMulticastDelegate::Broadcast() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\public\delegates\delegatesignatureimpl.inl:921]
UE4Editor_Engine!UWorld::Tick() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\engine\private\leveltick.cpp:1391]
UE4Editor_UnrealEd!UEditorEngine::Tick() [d:\build\++ue4+release-4.13+compile\sync\engine\source\editor\unrealed\private\editorengine.cpp:1408]
UE4Editor_UnrealEd!UUnrealEdEngine::Tick() [d:\build\++ue4+release-4.13+compile\sync\engine\source\editor\unrealed\private\unrealedengine.cpp:371]
UE4Editor!FEngineLoop::Tick() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\launch\private\launchengineloop.cpp:2834]
UE4Editor!GuardedMain() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\launch\private\launch.cpp:156]
UE4Editor!GuardedMainWrapper() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:202]
UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:264]
kernel32
ntdll

Fixed the problem, I had attempted to use the DOREPLIFETIME macro on a variable that had changed name and no longer existed.