Unreal Engine Issues
Unreal Engine Issues
Attempting to Open a Widget Blueprint With Animation and Timeline Panels Hidden Causes the Editor to Crash
UE - Editor - UI Systems - Nov 11, 2015When you attempt to open a widget blueprint when you have hidden the animation and timeline panels, the editor will crash. There is a workaround: Window->Reset Layout will allow you to open the blu ...
Cannot change Collision Responses once component is custom selected from scene
UE - Gameplay - Dec 27, 2016Cannot change Collision Response channel once component is custom selected from scene. This is only an issue if the component is selected by first selecting the actor in the world (scene), then sele ...
Hot Reload fails if a project and Engine are placed next to each other in the same root folder that has the same name as the project
UE - Foundation - Cpp Tools - Hot Reload - Jan 8, 2019Hot Reload does not work if a project and the Engine that project is associated with are placed next to each other in the same root folder that shares the same name as the project. During the Hot Re ...
[AI] Debug Render Scene Proxy hits ensure for registering a delegate twice during level streaming.
UE - AI - Debugging - Aug 31, 2022Description from licensee: We're seeing an ensure get tripped up in FDebugRenderSceneProxy that says "DrawDelegate is already Registered!". Debugging the issue, we have confirmed that the DrawDeleg ...
When using 'r.VT.SplitPhysicalPoolSize 64' with nanite meshes, mesh painting does not update in real time (only updates after stroke finished), duplicates mesh painting across separate instances of a mesh, and sometimes doesn't show up in PIE.
UE - Rendering - Architecture - Mar 3, 2025When using Mesh Painting on nanite meshes in 5.5 with 'r.VT.SplitPhysicalPoolSize' set to non-zero values (e.g. 16, 64), several issues occur, such as: 1. Painting doesn't update in real time (only ...
Destructibles using Form Extended structures with rigid body collision gives wrong hit result
UE - Simulation - Physics - Destruction - Jan 7, 2015DESCRIPTION: When using form extended structure with DMs that are hit by a rigid body the resulting hit does not reflect the correct actor if they are both using form extended. If a DM without form ...
Chaos : Rigid body sleeps when very small external force is applied by AddForce
UE - Simulation - Core - May 25, 2022When a small external force is applied to the rigid body, the VSmooth value is reset in the ResetVSmoothFromForces function. Since this function ignores the current velocity, a very small velocity ...
In 5.6, bWarningsAsErrors does not work with clang
UE - Foundation - Cpp Tools - UnrealBuildTool - Sep 20, 2025In 5.6, many warnings and errors specify their command line arguments to the compiler with these new C# attributes: [WarningsClangToolChain(["-Wno-date-time"], ["-Wdate-time", "-Wno-error=date-ti ...
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 ...
Attempting to use the GameplayTags module in a binary code project will result in build failures in Visual Studio.
UE - Foundation - Core - Mar 27, 2015Using the GameplayTags module in a code project created with the binary version of the Engine results in a build failure in Visual Studio. The following error is shown: 1> D:/Epic Games/4.7/Engine ...