Changing blueprint default values inside arrays only updates loaded child blueprints

UE - CoreTech - Jul 30, 2020

The rules for delta serialization in UE4 are complicated, and the editor tries to hide them from you, which works 90% of the time but can lead to confusion and data loss in other situations. In the ...

Cannot select child anim BPs for use in linked anim layers

UE - Anim - Runtime - Jul 15, 2021

From UDN: [Link Removed] Unable to set a Child ABP with inherited interface to a Linked Animation Layer Instance Class. I have a ABP_Biped which is our main ABP. I have the locomotion (idle+straf ...

Instanced Static Meshes ignore max World Position Offset Displacement for bounds after UpdateInstanceTransform is called

UE - Graphics Features - Jun 18, 2025

When an Instanced Static Mesh Component (ISMC) uses a material with a non-zero Max World Position Offset Displacement, the bounds are correctly expanded at initialization. However, after calling Upd ...

Render target size mistmatch in ShaderDrawDebug

UE - Graphics Features - Jun 9, 2020

We found a d3d debug validation assert in RDG_EVENT_NAME("ShaderDrawDebug"), with the full DLSS integration. It however also reproduces in  (4.25.1-release, dev-rendering and the plugin branch with ...

[CrashReport] TOctree<TVolumeLightingSample<3>,FLightVolumeOctreeSemantics>::TConstElementBoxIterator<TInlineAllocator<99,FDefaultAllocator> >

UE - Graphics Features - Oct 5, 2017

This Jira is a continuation of [Link Removed]. This is the same callstack which users are submitting, however the other Jira eventually got specific repro steps which were verified fixed in 4.17.0. ...

Unwanted black boundaries are displayed in a vertical split-screen with 3 players.

UE - Gameplay - Dec 2, 2019

Floating point error from UGameViewportClient::SplitscreenInfo causes this issue. FMath::TruncToInt( 3240 /*ViewportSize*/ * 0.333f/*Ratio in SplitScreenInfo*/ ) = 1079 I suggested a following t ...

[CrashReport] Access violation in UE4Editor_Engine!TOctree<TVolumeLightingSample<3>

UE - Graphics Features - Jun 14, 2017

This is a common crash in the 4.16 release. The callstack for the issue is essentially the same as [Link Removed], however that issue had confirmed repro steps and was verified fixed for 4.16.0. A ...

5.5 Static Mesh Import Pipeline Regression

UE - Editor - Content Pipeline - Import and Export - Apr 25, 2025

This question was created in reference to: [Link Removed] This post references the first post because this problem was not discovered till now. I think it was masked because the issue appears to be ...

Ongoing D3D 'HUNG' crash in FD3D11DynamicRHI::GetQueryData

UE - Graphics Features - Jan 18, 2017

This is a new ticket for the D3D 'HUNG' crash originally reported in [Link Removed]. Some fixes were introduced in 4.14.2 that decreased the occurrences of this crash, but other cases are still ongo ...

[CrashReport] UE4Editor_ShaderCore!FVertexFactory::Set() [vertexfactory.cpp:190]

UE - Graphics Features - Nov 17, 2017

This is a common crash in the 4.18 release. It is the exact same callstack (and crashGroup) as in [Link Removed], although that Jira had specific repro steps and was confirmed fixed in 4.18.0. The ...