Unreal Engine Issues
Unreal Engine Issues
Pre-UE5 serialized FVariant FVector data corruption when deserialized in UE5
UE - Framework - LWC - Jan 15, 2024FVariant is a struct that implements a union of data types, including FVector. When assigning an FVariant an FVector value in engine versions UE 4.27 or earlier, the FVariant will deserialize incorr ...
Calling UBlueprintMapLibrary::GenericMap_Find with a non-existent key causes a memory leak
UE - Framework - Blueprint - Apr 15, 2025When Calling UBlueprintMapLibrary::GenericMap_Find with a non-existent key, the function construct the default structure in-place on the given pointer without destroying the object. This behavior ca ...
Integer Blueprint variables reset the Bitmask Enum setting when the Editor closes
UE - Framework - Blueprint - Feb 28, 2019User created Bitmask flag Enumerators are not correctly stored and retrieved from Blueprint Integer variable settings. When the Editor is restarted the value of the Integer's Bitmask Enum is set to ...
In the GameUserSettings class, Landscape quality is not taken into account by GetOverallScalabilityLevel, but is changed by SetOverallScalabilityLevel.
UE - Gameplay - Oct 17, 2025Context: GameUserSettings stores user settings for a game, for example graphics and sound settings. The Scalability settings provide a way for to adjust the quality of various features in order to m ...
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 ...