Changing the ComponentClass of a ACharacter twice and trying to set a SkeletalMeshAsset crashes the engine

UE - Anim - Jan 22, 2026

Changing the ComponentClass of a ACharacter twice and trying to set a SkeletalMeshAsset crashes the engine with a "Cannot replace existing object of a different class" message. The conditions to re ...

[CrashReport] Access Violation - UModelComponent::GetPhysicsTriMeshData() [modelcomponent.cpp:673]

UE - Simulation - Physics - Oct 2, 2017

This is a trending crash coming out of the 4.18 Previews. Users have not provided any descriptions of their actions when the crash occurred. The callstack is similar to [Link Removed], which was ju ...

[CrashReport] Mac crash - FShaderCompilingManager::ProcessCompiledShaderMaps()

UE - Graphics Features - Nov 16, 2017

This is an infrequent Mac crash in the 4.18 release. The callstack is a match to [Link Removed] (loading Zen editor on Mac), but that was confirmed fixed for 4.18.0 while this continues for users. ...

iOS Launch On does not copy content to iOS/TVOS 13 devices

UE - Platform - Mobile - Aug 12, 2019

DeploymentServer fails to transfer the files LogPlayLevel: ********** DEPLOY COMMAND STARTED ********** LogPlayLevel: Running: F:\UE4-Release-4.23\Engine\Binaries\DotNET\IOS\DeploymentServer.exe ...

CRITICAL: Regression: CRASH: SHOOTERGAME: Client crashes when using ServerTravel command

UE - Networking - Sep 17, 2014

Update (5/4/15): New repro steps using Main (//depot/UE4/Promotable-CL-2535351): 1. Create a new Blueprint project 2. Create 3 new Levels: MainMenu, Lobby, and Level 3. Create 3 new GameModes: Main ...

Unreal Insights - GPU Timers don't show on Graph

UE - Metaverse - Profiling Tools - Oct 27, 2023

From Customer: UE 5.3 update broke Unreal Insights adding GPU timers into graph tracks. Debugging the code and cross checking with github/p4v I guess it broke in this revision: Timer graphs no ...

[CrashReport] UE4Editor-Slate.dylib!FMenuStack::PostPush(TSharedPtr<IMenu, (ESPMode)0>, TSharedRef<FMenuBase,()

Tools - Dec 1, 2017

This is a longstanding but infrequent Mac crash that has occurred since at least 4.15. Users have not provided any descriptions. Callstack from Log[2017.11.19-04.18.41:283][ 0]LogSlate: Took 0.000 ...

Nativized packaging fails when attaching paper Flipbook component to a parent paper Flipbook component that is Inherited.

UE - Gameplay - Blueprint - Jan 8, 2019

Nativized packaging fails when attaching paper Flipbook component to a parent paper Flipbook component that is Inherited. ...

Constraint axes are not visible in Physics Asset editor viewport

OLD - Anim - Jul 10, 2017

This is a regression from 4.16 as I was not able to repro this issue in //UE4/Release-4.16 at CL 3514769. ...

Changing the state of a PrimitiveComponent->BodyInstance while SetSimulatePhysics(false) updates the game thread but does not update the physics behavior

UE - Runtime - Simulation - Nov 21, 2024

Changing the state of a PrimitiveComponent->BodyInstance while SetSimulatePhysics(false) updates the game thread but does not update the physics behavior. In the repro project provided (see addl in ...