Unreal Engine Issues
Unreal Engine Issues
Nanite: unused VertexInterpolator node disables Opacity Mask (material renders opaque)
UE - Rendering - Architecture - Jun 8, 2026On Nanite meshes, placing a VertexInterpolator node in a material graph without using it (unconnected, or routed through a disabled static switch) silently breaks the Opacity Mask and the material r ...
ApplicationReceivedScreenOrientationChangedNotificationDelegate does NOT work properly on Android
UE - Platform - Mobile - Aug 5, 2019ApplicationReceivedScreenOrientationChangedNotificationDelegate supports iOS but not Android. Probably, Java_com_epicgames_ue4_GameActivity_nativeOnConfigurationChanged should be useful for fix thi ...
ensure(false) being fired in FGenericParticlePairMidPhase::FindOrCreateConstraint from key collision
UE - Runtime - Simulation - Jan 27, 2025ensure(false) being fired in FGenericParticlePairMidPhase::FindOrCreateConstraint from key collision. The licensee reports one of their users reported this issue and they were able to reproduce a fe ...
Spot Light USD Export Produces Incorrect Intensity Values Based on Cone Angle and Source Radius
UE - Editor - Content Pipeline - USD - Apr 3, 2026UPDATE: Should be fixed as of CL#52537078 (fb7af1) USD: Bake all frames of exposure animation tracks. When exporting Unreal Engine spot lights from a level to USD, lights with identical EV intensit ...
Reset to default behavior for arrays is inconsistent about updating customized struct headers
UE - Editor - Verse Class Editor - Jun 22, 2023The behavior for resetting the default for customized struct properties is inconsistent and needs to be reviewed and fixed. Currently we see this behavior:In non-array properties, the header will be ...
Linux: Assertion at splash screen when trying to open UE4Editor
UE - Platform - Linux - Mar 21, 2017I ran into this while looking to verify [Link Removed] at CL 3355923. I logged the issue I was verifying the fix for last night and have not updated anything locally, so the "OpenGL 4.3 not supporte ...
Inconsistent ListView entry sizes can prevent the ListView from being scrolled to the bottom
UE - AI Workflows - UI Systems - Slate - May 4, 2022Since the contents of a ListView are virtualized, the ListView estimates the size of the scroll box's contents based on the on-screen elements. This can lead to some situations where DistanceFromBot ...
Always Relevant actor may replicate incorrect movement mode when the walkable floor becomes irrelevant
UE - Runtime - Character - Feb 26, 2024When the character class is set to always relevant, if a client travels very far away from another character, such that the character is relevant but the component they're standing on is not (but al ...
Composite font uses a sub-font, even when the sub-font doesn't support the character
Tools - Apr 7, 2016I have a fix for this shelved in CL# 2937344, so it would be good to get it into 4.12 once the user verifies the fix. ...
MotionWarping does not recognize new MontageInstance with the same montage
UE - Characters - Animation - Jan 11, 2023When the same AnimMonotage is played again while moving with MotionWarping & RootMotion, UAnimNotifyState_MotionWarping does not recognize it. From licensee: The issue was that in URootMotionMod ...