Unreal Engine Issues
Unreal Engine Issues
HZB Occlusion causes large stalls on the render thread
UE - Rendering Architecture - RHI - Oct 7, 2025HZB 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, 2017Crash 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, 2014DESCRIPTION: 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, 2015Actors 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, 2025We'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 ...
Launch On from Windows to Linux fails with missing GLSL_430 shaders
UE - Platform - Linux - Nov 16, 2016GLSL_430 shaders are not cooked when deploying a project from Windows to Linux using Launch On. LogPlayLevel: PLINK: [31m[2016.11.16-18.36.22:414][ 0]LogMaterial:Error: The global shader cache fi ...
Capsule component Shape values can be glitched inside of Actor class bp
UE - Gameplay - Components - Oct 29, 2015Capsule 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, 2015Crash 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, 2025Some 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 ...
Using Tortoise SVN causes the engine's source control to be inconsistent
Tools - Jun 16, 2015If a user decides to use Tortoise SVN, the error messages given for needing to have things checked out is inconsistent. If there is a blueprint which references another blueprint, and the reference ...