Users project crashes when opening level that loads multiple sub-levels

UE - Foundation - Core - UObject - May 31, 2017

Users project crashes when opening level that loads multiple sub-levels. Unable to reproduce this in a clean project so the users project is provided though Epic's box account (link is in the repro ...

Cannot select child anim BPs for use in linked anim layers

UE - Anim - Runtime - Jul 15, 2021

From UDN: [Link Removed] Unable to set a Child ABP with inherited interface to a Linked Animation Layer Instance Class. I have a ABP_Biped which is our main ABP. I have the locomotion (idle+straf ...

Instanced Static Meshes ignore max World Position Offset Displacement for bounds after UpdateInstanceTransform is called

UE - Graphics Features - Jun 18, 2025

When an Instanced Static Mesh Component (ISMC) uses a material with a non-zero Max World Position Offset Displacement, the bounds are correctly expanded at initialization. However, after calling Upd ...

Render target size mistmatch in ShaderDrawDebug

UE - Graphics Features - Jun 9, 2020

We found a d3d debug validation assert in RDG_EVENT_NAME("ShaderDrawDebug"), with the full DLSS integration. It however also reproduces in  (4.25.1-release, dev-rendering and the plugin branch with ...

[CrashReport] UE4Editor-Engine.dylib!bool FHighResScreenshotConfig::SaveImage<FLinearColor>()

UE - Graphics Features - Jul 27, 2017

This is a common crash occurring on Mac in 4.15 and 4.16. Users have not provided any additional descriptions. Callstack from LogAssertion failed: Assertion failed: Bitmap.Num() == x * y [File:/Use ...

[CrashReport] UE4Editor_CoreUObject!FMemoryWriter::Serialize() [memorywriter.h:42]

UE - Foundation - Core - Jul 24, 2017

This is a common cook crash affecting users in 4.16. It is possibly the same issue as described in [Link Removed] for past engine versions. Source Context 33 virtual void Serialize(void* ...

[CrashReport] Crash on Mac during Editor load (out of memory loading Boot.ddc): Assertion failed: A.ArrayNum >= 0

UE - Foundation - Core - Jun 14, 2017

This is a common crash occurring for Mac users in the 4.16 release. It appears to occur during editor startup. The below details are taken from user log files.LogFileManager:Error: Requested read of ...

Unwanted black boundaries are displayed in a vertical split-screen with 3 players.

UE - Gameplay - Dec 2, 2019

Floating point error from UGameViewportClient::SplitscreenInfo causes this issue. FMath::TruncToInt( 3240 /*ViewportSize*/ * 0.333f/*Ratio in SplitScreenInfo*/ ) = 1079 I suggested a following t ...

[CrashReport] UE4Editor_Kismet!FBlueprintGraphArgumentLayout::OnArgNameChange()

UE - Gameplay - Blueprint Editor - Jul 19, 2017

This is a common crash affecting users in 4.16 and has been occurring since at least 4.14 affecting more than 300 unique users. User Descriptionsi made a macro called IsolateYaw and set the input t ...

[CrashReport] Assertion failed: !PinRef->bWasTrashed - UEdGraphPin::SerializePin()

UE - Gameplay - Blueprint - Sep 8, 2017

This is a common and longstanding crash that has affected more than 200 users since at least 4.15. This crashGroup was previously associated with [Link Removed], but that specific repro case has be ...