Instanced static meshes fire an erroneous performance assert about loose parameters.

UE - Graphics Features - Sep 4, 2019

 "This ensure is intended to catch regressions where rendering programmers add a loose parameter to LocalVertexFactory, breaking dynamic instancing on regular static meshes.  InstancedStaticMeshes c ...

GameInstance and subsystem initialization order is incorrect for Play In Editor

UE - Gameplay - May 18, 2023

The order of world and game instance initialization is different between a true standalone game (cooked game or an editor build with -game) and a Play In Editor game. Specifically, in Play in Editor ...

editor crashes when variable inside of a struct is set to a class type then the object is moved to a new folder

UE - Gameplay - Blueprint - Mar 17, 2015

If a struct has a variable set to a class type, then the object of that class type is moved to a new folder in the editor, the struct will replace the class type with "class", which causes the edito ...

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 ...

Crash when resizing window using Quad Stereo Buffer

UE - Virtual Production - nDisplay - Oct 2, 2019

We noticed crashes in our application when we attempted to resize a window or switch to full-screen mode. Hence, resizing windows and switching to full screen will result in a crash on Unreal Engine ...

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 ...

Unable to edit double variable in property matrix

UE - Editor - Workflow Systems - Oct 2, 2023

Since UE5.0, cannot edit double variables in property matrix. In UE4.27, it worked correctly and could be edited from the property matrix. This is because double variables are not supported in SProp ...