Ensure triggered in FBoundsCacheElement::GetValue when adding ISM instances in Construction Script

UE - AI - Oct 8, 2025

An ensure is triggered in FBoundsCacheElement::GetValue when adding instances to an InstancedStaticMeshComponent inside a Blueprint’s Construction Script. This occurs when the ISM component is navig ...

Section::TrimSection resulting in bad key values at start and end of trim range

UE - Anim - Sequencer - Dec 17, 2025

The trim process inserts keys at the start or end of the range depending if you specify Trim Left or Right, I'm finding that Trim right is inserting a key at the end of the section that is incorrect ...

VSCode finds intellisense errors in Project source files: cannot open source file "UBT_COMPILED_PLATFORM/UBT_COMPILED_PLATFORMPlatformCompilerPreSetup.h"

UE - Foundation - Cpp Tools - Jan 28, 2020

VSCode finds intellisense errors in Project source files: cannot open source file "UBT_COMPILED_PLATFORM/UBT_COMPILED_PLATFORMPlatformCompilerPreSetup.h" Similar to [Link Removed], but that was onl ...

Incorrect volume bounds check in FTranslucentLightInjectionCollector::AddLightForInjection

UE - Graphics Features - Apr 8, 2025

The 'VolumeBounds' array in FTranslucentLightInjectionCollector::AddLightForInjection is accessed as a pointer instead of with 'VolumeCascadeIndex' and thus fails bounds checks for the outer volume. ...

[CrashReport] Mac/Metal crash - Assertion failed: (PixelShader->Bindings.InOutMask

UE - Graphics Features - Nov 10, 2017

This is a low frequency but trending crash coming out of 4.18. User DescriptionsAttempting to open a copied/converted from 4.16.3 project on 4.18 preview 4. Problem arose after preview 3. Was able ...

Runtime Virtual Texture (RVT) baked mips using Streaming Virtual Texture (SVT) only bakes the base colour

UE - Graphics Features - Sep 13, 2024

Using Streaming Virtual Textures for the lower mips of an RVT using Base Color, Roughness, Normal seemingly leads to both roughness and normal being sampled as 0. This causes a significant shading a ...

Crash When Material is Set to Deferred Decal with Emissive Decal Blend Mode and Forward Shading Enabled

UE - Graphics Features - Jan 25, 2019

When Forward Shading is enabled, if you create a material with their properties setup with the following:   Material Domain: Deferred Decal - Blend Mode: Translucent - Decal Blend Mode: Emissive T ...

[CrashReport] Tutorial crash UObject::execLetValueOnPersistentFrame()

UE - Gameplay - Blueprint - Jul 7, 2017

This is another Tutorial crash that shares a similar callstack with [Link Removed] and [Link Removed], but those specific repro steps have been fixed while this one is still occurring in 4.16.2. On ...

[CrashReport] UE4Editor_Engine!FSceneView::FSceneView() [sceneview.cpp:627]

UE - Editor - UI Systems - Slate - Apr 11, 2017

Opening UE4.14 using thecommand line "-forceenablecrashtracker," results in a red circle on the top right of the editor that when clicked provides a link to a 20 second video recorded from when you ...

Exporting Alembic Skeletal mesh from UE4 to FBX causes a crash

Exporting an alembic skeletal mesh that has been imported and then exporting it to FBX using the asset actions options will cause a crash. Tested with: Crash - 4.13.0 Binary CL-3106830 Crash - 4.1 ...