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 ...

[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 ...

[CrashReport] Assertion failed: !PinRef->bWasTrashed | UEdGraphPin::SerializePin()

UE - Gameplay - Blueprint - Aug 29, 2017

This is a common and longstanding crash that has occurred since at least 4.15 and affected nearly 500 users. The CrashGroup was previously linked to [Link Removed], but that had specific repro step ...

[CrashReport] UE4Editor_Renderer!FUniformMeshConverter::Convert()

UE - Graphics Features - Aug 3, 2017

This is a regular crash that has occurred through 4.16 and into the 4.17 previews. The callstack is similar to [Link Removed] (invalid), although the error message is different. User Description ...

Player Character does not collide with landscape

UE - LD & Modeling - Terrain - Landscape - Mar 8, 2015

UPDATE: 3/9/2015 Additional Information: User on thread https://answers.unrealengine.com/questions/186928/landscape-collison-issues-recreatelandscapecollisi.html reported workaround did not fix e ...

UE4Editor_SlateCore!TSharedFromThis<SWidget,0>::AsShared() sharedpointer.h:1221

Tools - Apr 18, 2017

This bug report was entered as new crash groups appeared linking to [Link Removed] which was marked as fixed for 4.15.1 and the previous reproduction did not reproduce the issue Error message: Ass ...

Float Curve evaluation may yield completely wrong results due to floating-point precision issue

UE - Anim - Runtime - Oct 31, 2024

Note: This is possibly related to [Link Removed]. For some inputs, function UE::Curves::WeightedEvalForTwoKeys() inside file "CurveEvaluation.cpp" can incorrectly return the value of the first key, ...

Reference to control rig can be lost on actors with multiple skeletal mesh components

UE - Anim - Rigging - Control Rig - Apr 4, 2023

In the attached project, when we initially add a control rig track for the actor with multiple skeletal mesh components, we add the control rig for the correct component because FControlRigParameter ...

Changing blueprint default values inside arrays only updates loaded child blueprints

UE - CoreTech - Jul 30, 2020

The rules for delta serialization in UE4 are complicated, and the editor tries to hide them from you, which works 90% of the time but can lead to confusion and data loss in other situations. In the ...

Unfocused Standalone window has reduced performance

UE - Rendering Architecture - RHI - Aug 25, 2020

User description: When I run two windowed standalone instances to test multiplayer, the unfocused window gets about 2-5 fps...but if I focus on it, smooth 120fps, yet the opposite screen is now onl ...