Imported heightmaps with 2x2 sections crash editor

UE - LD & Modeling - Terrain - Landscape - Jul 18, 2016

Importing a heightmap with 2x2 segments seems to cause the editor to crash in 3 different instances: 1. Importing the same 2x2 segment landscape a second time after deleting the first instance 2. ...

[CrashReport] UE4Editor_Engine!UAnimMontage::IsValidAdditive() [animmontage.cpp:702]

OLD - Anim - May 19, 2016

Error message: Stack overflow - code c00000fd (first/second chance not available) Source Context: 687 if (SyncGroup != NAME_None) 688 { 689 CollectMarkers(); 690 ...

HZB Occlusion causes large stalls on the render thread

UE - Rendering Architecture - RHI - Oct 7, 2025

HZB Occlusion causes large stalls (greater than 5ms seen) on the render thread due to an RHI flush. This is caused by the following code in FDynamicRHI::RHIMapStagingSurface_RenderThread which force ...

Crash when pressing Ctrl-Z after creating a blueprint function

UE - Gameplay - Blueprint - Feb 20, 2017

Crash when pressing Ctrl-Z after creating a blueprint function *This is a regression: Working in 4.14.3-3249277 Not working in 4.15.0-3299760* Crash Reporter: Error message: Access violation ...

Form Extended Structures will only destroy one mesh but not any attached

UE - Simulation - Physics - Destruction - Nov 28, 2014

DESCRIPTION: While using form extended structures enabled for a Destruction mesh one of the meshes will be able to be damaged while any others attached will not fracture or damage at all. For exam ...

Actors in sublevels do not replicate to Clients after Seamless ServerTravel

UE - Networking - Dec 9, 2015

Actors in sublevels do not replicate to Clients after Seamless ServerTravel. The user reporting this noted that "[...] UNetDriver::IsLevelInitializedForActor() keeps returning false even when the ac ...

[Interchange] Crash on asset re-import

UE - Editor - Content Pipeline - Import and Export - Feb 7, 2025

We've started seeing a crash in editor when re-importing one of our assets. <pre class="ql-syntax">Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 783] Array index out of ...

Capsule component Shape values can be glitched inside of Actor class bp

UE - Gameplay - Components - Oct 29, 2015

Capsule component Shape values can be glitched inside of Actor class bp This effects 4.9.2 and 4.10 Preview 3, however it is working properly in 4.11-2736016 User Description: Alright, so the Cap ...

Crash when destroying a pawn on the client

UE - Networking - Jul 6, 2015

Crash when destroying a pawn on the client. Reproduced in 4.8.1 and Main (//depot/UE4/Promotable-CL-2610743). This is a regression: the crash does not occur in 4.7.6 Crash Report: [Link Removed] ...

[AI] Bad entries in NavigationRepository for Box collision with bCanEverAffectNavigation set to false

UE - AI - Navigation - Oct 26, 2025

Some components continue to dirty the navigation state even if bCanEverAffectNavigation is unchecked. Behavior appears very similar to an existing bug, [Link Removed] ([Link Removed]), which invol ...