Unreal Engine Issues
Unreal Engine Issues
Setting a struct bool property (bitfield) to itself writes the wrong value
UE - Framework - Blueprint Compiler - Sep 17, 2025There's an issue when assigning a bitfield bool to a native bool in Blueprints. Currently, the engine erroneously treats the memory for a local bool as a uint8 bitfield, which is undefined behavior. ...
[CrashReport] UE4Editor_Engine!FPointerToUberGraphFrame::~FPointerToUberGraphFrame()
UE - Gameplay - Blueprint - Aug 15, 2017This is a trending crash coming out of the 4.17.0 release. Users have not provided any descriptions of their actions when the crash occurred, however the callstack is very similar to [Link Removed] ...
[CrashReport] UE4Editor_Landscape!FLandscapeComponentSceneProxy::FLandscapeComponentSceneProxy() [landscaperender.cpp:680]
UE - LD & Modeling - Terrain - Landscape - Apr 11, 2018User comment in crash group:Wanted to delete a single field of my landscape wich is very big. Same error appears if I try to get a part of the landscape to another streaming level. Would be cool if ...
CheckCompilingPSOs assert in FMaterialPSORequestManager::MarkCompilationComplete fires occasionally
UE - Rendering - Architecture - RHI - May 17, 2025Find the root cause and fix it. Potential issue based on logs:New RequestA is created in PrecachePSOs and its collection task is dispatched and finishedRequestA is waiting for compilation taskReque ...
LevelStreamingPersistence: BP variables that aren't Instance Editable get reset
UE - World Creation - Worldbuilding Tools - Mar 6, 2026Context The LevelStreamingPersistence plugin can be used to remember and restore properties on actors and components that are part of a streamed level. Blueprint variables can be marked as instan ...
Compile error in ShadowDepthVertexShader.usf if INTERPOLATE_POSITION
UE - Graphics Features - Oct 21, 2015Shader compile error in function PositionOnlyMain() in ShadowDepthVertexShader.usf if defined INTERPOLATE_POSITION. LogShaderCompilers:Warning: 1 Shader compiler errors compiling WorldGridMaterial ...
Undo/Redo can cause the gizmo to desync from a leaf-selected component
UE - Editor - Oct 18, 2021This is a regression from 4.27. This is happening because of the change to typed elements. UEditorEngine::PostUndo, when combined with the typed element changes causes the selection set to reorder ...
AbilityTask_PlayMontage will 'zombie' if Interrupted during BlendOut
UE - Gameplay - Gameplay Ability System - Apr 14, 2023User reports: I've noticed a bug with PlayMontageAndWait There are 4 possible triggers when a Montage completes:OnCompletedOnBlendOutOnInterruptedOnCancelled Once OnBlendout has been triggere ...
Niagara module inputs don't handle bitfield enums correctly
UE - Niagara - Feb 17, 2025As one clicks on the enum fields trying to form an input, the log is written with a variation of the following: [2025.02.14-17.42.38:940][521]LogNiagaraEditor: Error: Error getting default value fo ...
Orphaned BP actors when using UWorldPartitionBuilder
UE - World Creation - Worldbuilding Tools - World Partition - Nov 21, 2025From an EPS case: --------------------------------- We're seeing a recurring issue where child BP actors are becoming orphaned during any processing that uses UWorldPartitionBuilder. It affects ...