Actor in Map in Struct Causes Crash When Changed

UE - Gameplay - Blueprint - Mar 8, 2018

User submitted bug. Editor will crash after changing key or value in Map. ...

Auto-Save failing, pulling old saves and blocks users from continuing

UE - Editor - Workflow Systems - May 15, 2023

Reporting an issue where are users are getting prompted to auto-save, but then it appears to fail and asks them to manually save. They're being prompted with outdated save files, but get stuck in a ...

Renaming a level by WorldPartitionRenameDuplicateBuilder fails if the level contains GroupActor with non-spatial actors

UE - World Creation - Worldbuilding Tools - World Partition - Oct 24, 2023

Referece to the source level should be fixed by FReplaceObjectRefsArchive, but it is not working because ArIsModifyingWeakAndStrongReferences is not set. It can be fixed by setting the flag.class FR ...

[CrashReport] Access violation - FLandscapeEditDataInterface::SetAlphaData()

UE - LD & Modeling - Terrain - Landscape - Jul 19, 2017

This is a common crash affecting users in 4.15 and 4.16. This callstack was previously linked to [Link Removed], but that had a specific repro case that was fixed in 4.14. Users are not providing ...

Crash when quick binding a function in a class that extends LevelSequenceDirector

UE - Anim - Sequencer - Sep 16, 2020

The purpose was to create a Level Sequence Director inheritance class so that the same event could be reused in multiple sequencers. Attempting to quick-bind this base Level Sequence Director event ...

FAnimationRuntime::BlendPosesPerBoneFilter() causes an assertive crash when Skeletal Mesh LOD is changed

UE - Anim - Runtime - Nov 1, 2023

The crash occurs from "check(BoneBlendWeights.Num() == NumBones);" This crash occurs when the following conditions are met;The skeletal mesh LOD is changed.The number of bones is difference between ...

Switch on custom enum causes compilation errors after Hot Reload

UE - Foundation - Core - Sep 28, 2015

If the project is hot reloaded while a Switch on Enum is inside of a blueprint which is switching on a custom enum, the switch will become corrupted. It changes the 'selection' pin to take a Byte pa ...

Hardware Lumen Surface Cache Artifacts on Nanite Geometry

UE - Graphics Features - Lumen - Sep 1, 2025

When using Hardware Lumen with Nanite-enabled meshes in UE 5.6+, black / dark surface cache artifacts appear that result in generally darker and unstable lighting. These artifacts are not immediatel ...

[CrashReport] UE4Editor_D3D11RHI!TerminateOnDeviceRemoved() [d3d11util.cpp:176]

UE - Graphics Features - Nov 18, 2016

Error message: Fatal error: [Link Removed] [Line: 176] Unreal Engine is exiting due to D3D device being lost. (Error: 0x887A0006 - 'HUNG') Source Context: 161 162 const TCHAR* Rea ...

[CrashReport] UE4Editor_Core!FText::FText() [text.cpp:165]

Tools - Jan 12, 2017

This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Descriptions from users are provided below. Error message: Access violation - code c0000005 ( ...