Unreal Engine Issues
Unreal Engine Issues
Substrate SSR reflections are black
UE - Rendering - Features - Shading Models - Dec 17, 2024Substrate Materials do not use Screen-Space reflections. Instead, they do not have any reflections (indirect specular) on the surface. ...
Soft angular constraints solve velocity like hard constraints
UE - Runtime - Simulation - Jul 17, 2025Soft angular constraints are solving velocity like hard constraints. Instead of swinging back and forth, the affected body just snaps to 45 degrees. Check the steps to reproduce for more details. Th ...
HISM causing massive spikes in BuildTreeAsync
UE - Rendering - Architecture - Feb 12, 2026Loading a world partition cell containing dense foliage (30k+ instances per cell) causes spikes on lower end hardware of up to 10-15ms and can observe spikes of 2-5ms on high end hardware too primar ...
Packaged Game Crashes When Launched with the -dx12 for Ray Tracing Features and PixelStreaming enabled
PixelStreaming - Apr 3, 2019Packaged game crashes when launched with the -dx12 option and PixelStreaming is enabled. Found in 4.22 CL# 5660361 and 4.23 CL# 5704223 ...
Crash when trying to change game mode settings
Trying to change game mode settings after restarting the editor will cause the editor to crash. ...
Setting character animation in parent BP and mesh in child BP does not play the animation in a packaged game
UE - Gameplay - Jan 21, 2015When a child BP is used to with a skeletal mesh to play an animation set in the parent, the animation will play in editor and in standalone but will not play in a packaged game. ...
LIVE: Attach Actor to Component crashes the editor when used after Set Simulate Physics
UE - Simulation - Physics - Oct 31, 2014The user has attached a small project at the link to demonstrate the issue. Occurs in 4.5.1 and well as Main (//depot/UE4/Promotable-CL-2239587). Crash Reporter: [Link Removed] ...
Load level interactions are not working on mobile
UE - Editor - UI Systems - Dec 9, 2014When using UMG to load levels on a mobile device, The first level is being loaded but nothing after the first is able to trigger any additional levels to load. ...
The World Outliner will only show one Child Actor on a Blueprint that has multiple Child Actors in its Components tab
Tools - Apr 13, 2015The World Outliner will only show one Child Actor on a Blueprint that has multiple Child Actors in its Components tab. Note that all Child Actor Components added via the Construction Script will dis ...
Setting NavModifierVolume's AreaClass at runtime does not result in navmesh rebuilding
UE - AI - Apr 23, 2015The volume does accept the change and if it gets moved the navmesh will rebuild with new area set. The core issue is that setting NavModifierVolume.AreaClass at runtime does not notify navigation sy ...