If a custom code class is modified and a Hot Reload performed, any existing unsaved Blueprints derived from that class can no longer be saved.

UE - Gameplay - Blueprint - Feb 19, 2015

When a custom code class is changed and a Hot Reload is performed, any Blueprints previously made from that class can no longer be saved. Possibly related to [Link Removed]. WORKAROUND: Close and ...

Hierarchical LODs used with Precomputed Visibility cause actors to occlude that should not behind translucent materials

UE - Graphics Features - Jul 6, 2016

When using Precomputed Visibility in conjunction with HLODs and translucent materials without them culling actors occluded by the translucent material. The example gif attached shows that the base ...

[CrashReport] UE4Editor_ShaderCore!FShader::GetVertexShader() [shader.h:568]

UE - Graphics Features - Nov 21, 2017

This is a common and longstanding crash that has occurred since at least 4.16 User DescriptionsTrying to paint my new sandtexture onto the terrainOpened the material editor by double clicking a mat ...

[CrashReport] UE4Editor_Renderer!FMaterialShader::SetParametersInner<FRHIVertexShader * __ptr64>() [shaderbaseclasses.cpp:181]

UE - Graphics Features - Jun 19, 2018

No user comments in crash group 172 const bool bOverrideSelection = 173 GIsEditor && 174 !View.Family->EngineShowFlags.Selection && 175 (MaterialRenderProxy- ...

ChaosCacheManager is not properly recording the state of each particle when toggling Fields and Anchor Fields in the scene.

UE - Simulation - Physics - Destruction - Oct 22, 2024

ChaosCacheManager is not properly recording the state of each particle when toggling Fields and Anchor Fields in the scene. During my investigations I've noticed that ChaosCacheManager does not reco ...

The Remove-On-Break feature, set on Fracture Mode on Geometry Collections, stops shrinking and shows strange behaviors

UE - Simulation - Physics - Destruction - Oct 15, 2024

The Remove-On-Break (ROB) feature, set on Fracture Mode on Geometry Collections (GC), was supposed to make the particle shrink until it vanishes. When the GC goes to sleep the shrinking stops and sh ...

Crash with for loop and TArray in constructor to generate multiple StaticMeshComponents

UE - Foundation - Core - Apr 20, 2015

Using a TArray to store multiple components being setup inside a for loop of a constructor will crash on project open. Crash Reporter: [Link Removed] ...

Changing the “show mouse cursor” variable of PlayerController with a mouse button input does not work the same as with a keyboard input

UE - Editor - UI Systems - Slate - Oct 6, 2020

Using the mouse input to show the mouse cursor acts like an Alt+Tab. When clicking the mouse input again to no longer show the cursor, the camera controls stop at the edge of the screen. Reported i ...

Make Bitmask node returns incorrect value when using custom Enum

UE - Gameplay - Blueprint - Jul 5, 2016

When a custom enum is used as the Bitmask Enum of a Make Bitmask node, the value returned does not match the expected value ...

Opcode shader compilation error when using a TextureSampleParameterCubeArray node with hardware ray tracing enabled

UE - Graphics Features - Ray Tracing - Mar 31, 2025

Materials containing a cube array texture sampling node will not compile when hardware ray tracing is enabled. The shader compilation error indicates that an invalid op code was used: "Opcode Sample ...