Calling UBlueprintMapLibrary::GenericMap_Find with a non-existent key causes a memory leak

UE - Framework - Blueprint - Apr 15, 2025

When 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 ...

Child Actor Component Actor Duplicates and Persists After Play

UE - Gameplay - Sep 26, 2019

When an actor spawns another actor using AddChildActorComponent that comes alphabetically before it based on blueprint name it will spawn an extra actor that will persist when the scene is stopped d ...

Using a FormatText node with Specifier in the same graph as an empty Macro will freeze the editor

UE - Gameplay - Blueprint - Jun 17, 2016

Using a FormatText node with Specifier in the same graph as an empty Macro will freeze the editor. Not using the Specifier or deleting the unused Marco will allow the BP to compile fine. **Only rep ...

Integer Blueprint variables reset the Bitmask Enum setting when the Editor closes

UE - Framework - Blueprint - Feb 28, 2019

User 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 ...

Camera Movement is laggy while the mouse button is held down and ShowMouseCursor is enabled if there are AI moving

UE - Gameplay - Dec 15, 2015

Camera Movement is laggy while the mouse button is held down and ShowMouseCursor is enabled if there are AI moving. Stat Scene Rendering didn't show any jumps while moving the camera under these cir ...

PhysX Crash when spawning Instanced Static Mesh actors at Runtime

UE - Simulation - Physics - Destruction - Oct 13, 2015

Bug generated from crash reporter. This crash has been found in 4.7.6 and still occurs in 4.8.3 and 4.9.2 to users. One user in particular still, and he experiences it often. I have not been able ...

AMD GPU crash with "Video memory has been exhausted" error when increasing the World Partition world and using Water Body Ocean

UE - Graphics Tools - Terrain - Landscape - Dec 8, 2022

Current steps describe the problem related to "Video memory has been exhausted (#### MB over budget). Expect extremely poor performance" on the AMD video card. In this case, the steps cause the GPU ...

[AI] Debug Render Scene Proxy hits ensure for registering a delegate twice during level streaming.

UE - AI - Debugging - Aug 31, 2022

Description 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, 2025

When 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 ...

When multiple actors are selected, they have different undo behavior in the details panel

UE - Editor - Workflow Systems - Nov 15, 2021

When the text in spinbox has focus, it doesn't get the change notification externally. It may also be worth noting that ctrl z or ctrl y also do not get bubbled up to undo the text box values. It a ...