Editor can crash while performing a Hot Reload after a custom UClass class is added to the project

UE - Foundation - Cpp Tools - Hot Reload - Mar 14, 2019

Performing a Hot Reload after creating a custom UClass class can result in a crash. This was reported on Linux, but reproduced on Windows. Additional testing will be done on Linux to confirm the is ...

Using ConstructorHelpers::FClassFinder in a GameMode constructor may result in a default value or crash if the level is reloaded multiple times.

UE - Gameplay - Oct 27, 2015

Randomly selecting a character class from the GameMode constructor using ConstructorHelpers::FClassFinder can result in default or null character being set when the level is reloaded. It appears tha ...

.glTF importer crash - UE4Editor-GLTFImporter!ImportStaticMesh

OLD - Enterprise - Nov 14, 2018

Enabling the gLTF plugin and trying to import a glTF asset results in a crash. ...

Server crashes when client connects after Server has reloaded a sublevel with a deleted actor

UE - Networking - Jul 13, 2017

UNetDriver::DestroyedStartupOrDormantActors maintains a list of deleted startup (and dormant) actors. This is used to notify clients that have joined the server of Actors that need to be destroyed ...

Out-of-Bounds Access During Partial Updates of ISMC Per-Instance Custom Data

UE - Graphics Features - Jan 6, 2026

When using instance custom data values, removing an instance and changing the number of custom data floats in sequence can cause an array-out-of-bounds crash. The underlying arrays are not resized ...

Client crash on seamless travel in DataReplication with lag

UE - Networking - Jan 11, 2016

When server traveling, client may crash due to lag while attempting to replicate object/property. ...

RewindDebugger draws debug capsules with its base location as center

UE - Anim - Oct 31, 2024

Context UE_VLOG macros can be used to capture debug shapes into both a Visual Logger recording and a Rewind Debugger recording. Problem In the Rewind Debugger, the capsule shapes are drawn at an in ...

Making changes to a Camera Shake while previewing the Camera Shake triggers a crash

UE - Anim - Sequencer - May 23, 2022

This is not a regression. Tested in //UE4/Release-4.27 CL 18319896  Making changes to a Camera Shake while previewing the Camera Shake triggers an Assertion upon compiling. ...

Crash when deleting the Add Component By Class node after changing the Relative Transform of the component

UE - Gameplay - Blueprint - Mar 31, 2021

When adding the Add Component By Class node, choosing a class that has a Relative Transform pin, changing the transform, and deleting the node the editor crashes. I tested this with the Skeletal Mes ...

Deleting elements from TMap Struct in actor blueprint editor causes Crash

UE - Editor - UI Systems - Slate - May 24, 2019

Deleting elements from TMap Struct in the Actor Blueprint Editor (specifically, deleting elements from them) causes Unreal to crash ...