This is a common and longstanding crash that has occurred since at least 4.11.
User Descriptions
no source context available
repro steps unknown
Access violation - code c0000005 (first/second chance not available) UE4Editor_UdpMessaging!FUdpMessageProcessor::HandleSerializedMessageStateChanged() [udpmessageprocessor.cpp:548] UE4Editor_UdpMessaging!TBaseRawMethodDelegateInstance<0,FUdpMessageProcessor,void __cdecl() [delegateinstancesimpl.h:648] UE4Editor_UdpMessaging!FUdpSerializeMessageTask::DoTask() [udpserializemessagetask.cpp:58] UE4Editor_UdpMessaging!TGraphTask<FUdpSerializeMessageTask>::ExecuteTask() [taskgraphinterfaces.h:784] UE4Editor_Core!FTaskThreadAnyThread::ProcessTasks() [taskgraph.cpp:910] UE4Editor_Core!FTaskThreadAnyThread::ProcessTasksUntilQuit() [taskgraph.cpp:786] UE4Editor_Core!FTaskThreadBase::Run() [taskgraph.cpp:502] UE4Editor_Core!FRunnableThreadWin::Run() [windowsrunnablethread.cpp:76]
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-52624 in the post.