Unreal Engine Issues
Unreal Engine Issues
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 ...
Switching a code project created in a source-built Engine to use the binary Engine results in files being deleted from the binary Engine installation
Tools - Nov 18, 2016If a code project is created in an Engine built from source code, and then it is switched to use a binary Engine installed by the Launcher, building the project in Visual Studio will result in numer ...
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
zComponent - Archive - 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 ...
[CrashReport] Linux crash - FLinuxSplashState::InitSplashResources()
UE - Platform - Linux - Oct 27, 2017This is a trending Linux crash in 4.18. It seems to occur before a project loads. Callstack from Log[2017.10.27-08.31.13:659][ 0]LogInit: - Physical RAM available (not considering process quota) ...
Crash on garbage collection - Encountered 20 object(s) breaking GC Clusters assumptions.
UE - Foundation - Core - Aug 15, 2018Garbage collection crash during opening cinematic. Note after crashing and relaunching the game the saved file appears as 8% complete instead of 0%. Note this crash is also occurring with //UE4/D ...
Crash when removing and re-adding instances to an InstancedStaticMeshComponent with PerInstanceCustomData.
UE - Engine Scaling - Streaming - Jan 22, 2026When using an InstancedStaticMeshComponent with PerInstanceCustomData, the number of float elements in the "Custom Data" array should always be equal to NumCustomDataFloats multiplied by the number ...
[Enhanced Input] Chord trigger fails when its referenced action lives in a lower-priority IMC
UE - Gameplay - Input - May 18, 2026Summary A UInputTriggerChordAction does not fire when the action it references (the "chording action") is mapped in a different Input Mapping Context with a lower priority than the IMC containing the ...