Unreal Engine Issues
Unreal Engine Issues
UAbilityTask_SpawnActor::BeginSpawningActor may return true when SpawnedActor contains stale value
UE - Foundation - Mar 15, 2026UAbilityTask_SpawnActor::BeginSpawningActor assumes the incoming AActor*& SpawnedActor parameter is nullptr if no actor was spawned, but it does not initialize the parameter at the start of the func ...
Crash when opening a level with skeletal mesh asset from the map copied to the clipboard
UE - Foundation - Core - Jul 28, 2016Navigating to a level with a skeletal mesh asset from that level copied to the clipbard from the world outliner will cause the editor to crash. This can currently only be reproduced in the TM-Contac ...
Crash in Skeletal Editor due to null ActorFactory reference
OLD - Anim - Feb 1, 2017When a material is dragged/dropped into a skeletal editor's bone hierarchy, the editor will crash due to null ActorFactory Regression: Yes - Crash does not occur in 4.13.2 binary (CL 3172292) ...
Packaging fails after changing from Dynamic to Static Nav Mesh Runtime Generation
UE - AI - Feb 8, 2016If you package with Runtime Generation set to Dynamic and then switch to Static and attempt to repackage, the packaging will fail with the following error message.[2016.02.08-16.18.14:511][217]MainF ...
Thare are some case in which KeepState doesn't work propely if level sequence have multiple Shot and Transform Tracks
UE - Anim - Sequencer - Feb 16, 2021if fulfilling following conditions, KeepState setting of transform track doesn't work.level sequence have 3 or more shot have camera track and actor track have transform tracktransform track of acto ...
StreamableManager completion callback can happen after being canceled in same frame
UE - CoreTech - Feb 16, 2024FStreamableHandle (used as part of the FStreamableManager system) has a CancelHandle function that stops it from calling any completion callbacks related to that handle (it could cancel the load req ...
Controller::OnPossessedPawnChanged broadcasts (Pawn->null) but not (null->Pawn) during AGameModeBase::RestartPlayer()
UE - Gameplay - Sep 17, 2025Context AController has a blueprint assignable delegate that fires when the possessed pawn changes. This should fire in both singleplayer and networked games. The bug is reproducible in single play ...
DynamicWind doesn't unregister proxy and leaks
UE - Rendering - Architecture - Mar 20, 2026FSkinnedSceneProxy's never get unregistered from the DynamicWind system In FDynamicWindTransformProvider::UnregisterSceneProxy, there's an early out that says: if (SkinningSceneExtProxy == nullptr ...
Opening Materials and Material Functions with Vertex Interpolator node Results in Crash
UE - Graphics Features - May 23, 2018Per Licensee: Hello, We are migrating our project from 4.18 to 4.19.2 and we are encountering various crashes while opening our material and material functions. I'm adding a simple test case here. ...
Crash: Direct3DDevice->CreateBuffer failed at D3D11VertexBuffer.cpp with error E_INVALIDARG
UE - Graphics Features - Jul 6, 2017This is a common crash affecting users since at least the 4.14 release. It was previously associated with [Link Removed], however that has been marked as fixed. Source Context 221 void Veri ...