Imported heightmaps with 2x2 sections crash editor

UE - LD & Modeling - Terrain - Landscape - Jul 18, 2016

Importing a heightmap with 2x2 segments seems to cause the editor to crash in 3 different instances: 1. Importing the same 2x2 segment landscape a second time after deleting the first instance 2. ...

[CrashReport] UE4Editor_Engine!UAnimMontage::IsValidAdditive() [animmontage.cpp:702]

OLD - Anim - May 19, 2016

Error message: Stack overflow - code c00000fd (first/second chance not available) Source Context: 687 if (SyncGroup != NAME_None) 688 { 689 CollectMarkers(); 690 ...

HZB Occlusion causes large stalls on the render thread

UE - Rendering - Architecture - RHI - Oct 7, 2025

HZB Occlusion causes large stalls (greater than 5ms seen) on the render thread due to an RHI flush. This is caused by the following code in FDynamicRHI::RHIMapStagingSurface_RenderThread which force ...

Crash when pressing Ctrl-Z after creating a blueprint function

UE - Gameplay - Blueprint - Feb 20, 2017

Crash when pressing Ctrl-Z after creating a blueprint function *This is a regression: Working in 4.14.3-3249277 Not working in 4.15.0-3299760* Crash Reporter: Error message: Access violation ...

[CrashReport] Fatal Error: Ran out of memory - GenerateInstancedStereoCode() shadercompiler.cpp

UE - Rendering - Architecture - RHI - Nov 10, 2017

This is a trending crash coming out of the 4.18 release. Users have not provided any descriptions of their actions when the crash occurred. Source Context 174 if (GWarn) 175 { ...

Form Extended Structures will only destroy one mesh but not any attached

UE - Simulation - Physics - Destruction - Nov 28, 2014

DESCRIPTION: While using form extended structures enabled for a Destruction mesh one of the meshes will be able to be damaged while any others attached will not fracture or damage at all. For exam ...

Actors in sublevels do not replicate to Clients after Seamless ServerTravel

UE - Networking - Dec 9, 2015

Actors in sublevels do not replicate to Clients after Seamless ServerTravel. The user reporting this noted that "[...] UNetDriver::IsLevelInitializedForActor() keeps returning false even when the ac ...

[Interchange] Crash on asset re-import

UE - Editor - Content Pipeline - Import and Export - Feb 7, 2025

We've started seeing a crash in editor when re-importing one of our assets. <pre class="ql-syntax">Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 783] Array index out of ...

Substrate Single Layer Water material fails to compile in blendable Gbuffer mode when using the Single Layer Water BSDF node

UE - Graphics Tools - Terrain - Water - Jun 16, 2026

When using Substrate in Blendable GBuffer mode, a material with the single layer water BSDF node produces a shader compiler error : MaterialEditorStats: Error: [SM6] Shader debug info dumped to: "\ ...

Launch On from Windows to Linux fails with missing GLSL_430 shaders

UE - Platform - Linux - Nov 16, 2016

GLSL_430 shaders are not cooked when deploying a project from Windows to Linux using Launch On. LogPlayLevel: PLINK: [2016.11.16-18.36.22:414][ 0]LogMaterial:Error: The global shader cache fi ...