Unreal Engine Issues
Unreal Engine Issues
Changing blueprint default values inside arrays only updates loaded child blueprints
UE - Core - Systems - Jul 30, 2020The 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 - Runtime - Animation - Jul 15, 2021From 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 - Rendering - Features - Jun 18, 2025When 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, 2020We 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 ...
Wrong density calculation in UBodySetup::CalculateMass
UE - Runtime - Simulation - Sep 29, 2025Wrong density calculation in UBodySetup::CalculateMass. The licensee has provided the following analysis and suggested fix: In UBodySetup::CalculateMass, the following code is present: // physical ...
Unwanted black boundaries are displayed in a vertical split-screen with 3 players.
UE - Gameplay - Dec 2, 2019Floating point error from UGameViewportClient::SplitscreenInfo causes this issue. FMath::TruncToInt( 3240 /*ViewportSize*/ * 0.333f/*Ratio in SplitScreenInfo*/ ) = 1079 I suggested a following t ...
SimpleStreamableAssetManager: Memory Bloat/Leak in AssetIndexToBounds4Index
UE - Engine Scaling - Streaming - Feb 3, 2026Overview: A report has been received regarding a memory leak that eventually leads to OOM crashes when s.StreamableAssets.UseSimpleStreamableAssetManager=1 is enabled. In projects that utilize this ...
5.5 Static Mesh Import Pipeline Regression
UE - Editor - Open File Formats - Import and Export - Apr 25, 2025This 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 ...
[PCG Mode] Tool actors spawned by PCG Editor Mode tools ignore the current level and are always created in the PersistentLevel
UE - Graphics Tools - PCG - Procedural Tools - Oct 21, 2026Summary In a non-World-Partition map with streamed sublevels, PCG Editor Mode interactive tools (Draw Spline / SpacingTool, Area, Paint, Volume, ...) spawn their new tool actor in the PersistentLevel ...
Ongoing D3D 'HUNG' crash in FD3D11DynamicRHI::GetQueryData
UE - Graphics Features - Jan 18, 2017This 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 ...