Crash: Changing Material Property Overrides of Material Instance

UE - Graphics Features - Dec 14, 2016

When a material has a static bool parameter AND this is overridden in a material instance, Trying to change Blend Mode or Shading Model under the Material Property Overrides crashes the editor. Thi ...

[CrashReport] UE4Editor_Sequencer!FSequencer::Tick() [sequencer.cpp:439]

UE - Anim - Sequencer - Aug 21, 2017

This is a common crash that has occurred since at least the 4.10 release, although there seems to be a gap where it may not have occurred through the 4.12-4.14 releases, but returned with 4.15. Use ...

Navigation mesh is generated ignoring collision for ISM added by construction script

UE - Runtime - Character - Apr 15, 2025

When opening a map with ISM in place, NavOctree is not updated because the ISM bounds are assumed invalid and the geometry is not taken into account in the navmesh build.  The following log output i ...

Setting a float variable to a value that's beyond the maximum value of a float causes the editor to become unresponsive

UE - AI Workflows - UI Systems - Localization - Nov 12, 2021

When inputting an extreme large value into a float variable that exceed the maximum value of a float, the engine then becomes unresponsive. I tested this with an integer variable and this did not oc ...

Light as If Static setting does not Persist when Re-opening Project

Tools - Apr 28, 2016

This bug was originally entered back in 4.8 as [Link Removed], but was closed as by design. The reason was, the mesh did not have Lightmap UVs, so using the 'Light as If Static' option would not wor ...

Renaming Parameters resets all Instances in Level and Thumbnails

UE - Rendering - Architecture - Materials - Jan 27, 2015

Renaming a Parameter in a Base Material will make all instances of that Base Material in the level and the instance's thumbnail reset to default values from Base Material until the Instance is opene ...

[CrashReport] UE4Editor_Core!FFileHandleWindows::Seek() [windowsplatformfile.cpp:501]

UE - Foundation - Core - Aug 29, 2017

This is common crash coming out of the 4.17 and 4.18 releases. The callstack is similar to an old unresolved import crash: [Link Removed] User Descriptionsrebuilding lightbuilding lighting from a d ...

[CrashReport] UE4Editor_UnrealEd!TArray<TSharedRef<FAssetThumbnailPool::FThumbnailInfo,0>,FDefaultAllocator>::AddUniqueImpl<TSharedRef<FAssetThumbnailPool::FThumbnailInfo,0> const & __ptr64>() [array.h:1805]

Tools - Sep 20, 2017

This is a longstanding crash that occurs with low frequency per release, but has affected 400 users since the 4.11 release. Unfortunately among all of them, only one has provided any description. ...

[CrashReport] UE4Editor_D3D11RHI!FD3D11DynamicRHI::GetQueryData() [d3d11query.cpp:111]

UE - Graphics Features - Apr 12, 2018

One comment from user in crash group:checking out using source control 107 bool bGPUAlive = GDynamicRHI->CheckGpuHeartbeat(); 108 if (!bGPUAlive) 109 { 110 ***** ...

Crash When Loading Cooked Material Assets in Editor Due to Shader Serialization

UE - Rendering - Architecture - Shaders - Aug 27, 2025

In Unreal Engine 5.6+, the new shader serialization logic in FShaderMapResourceCode::Serialize does not correctly handle cooked assets that are loaded back into the editor (e.g., from a mounted .pak ...