Unreal Engine Issues
Unreal Engine Issues
UClass::SparseClassDataStruct null at editor-time for child blueprints until compile
UE - Framework - Blueprint - May 29, 2024Child blueprints of a blueprint of a native actor class with sparse data can have an incorrectly null SparseClassDataStruct value, and thus fail to initialzie their SparseClassData. This affects edi ...
"Landscape Layer" Doesn't appear in LandscapeMode even when the landscape is assigned a Layer-Based Material
UE - Graphics Tools - Terrain - Aug 19, 2026POST LINK: https://forums.unrealengine.com/t/bug-ue5-8-1-landscape-layer-doesnt-appear-in-landscapemode-even-when-the-landscape-is-assigned-a-layer-based-material/2745109 POST BODY:Summary[Bug][UE5 ...
Thirdperson Character not Replicating correctly after being attached to an Actor
UE - Networking - Dec 20, 2017Problem description: When the Third Person Character gets attached to any other Actor (AttachToActor, Rule: Keep World), from the view of other clients the character (capsule, skeletal mesh) is out ...
Sequencer fails to package during Build command for ASTC
UE - Platform - Mobile - Jan 15, 2017When attempting to test for ESDSR on Android, the Sequencer project fails to package towards the end of the Build Command. Runtime/OpenGLDrv/Public\OpenGLESDeferred.h(267,5) : warning: 'OPENGL_ES2 ...
Combining Layered Blend Per Bone with Cached Pose nodes can break root motion extraction
UE - Characters - Animation - Aug 23, 2023When the input to a Layered Blend Per Bone node is two instances of the same cached pose, we aren't sampling root motion correctly. In the attached example, the weight on the root bone is 0 and Ble ...
"Enable Stencil Test" Mobile crash
UE - Graphics Features - Sep 10, 2019A material with 'enable stencil test' will crash on mobile. Enable Stencil Test is a new option in materials as of 4.23 Confirmed with OpenGL 3.1 + 2 and Vulkan on Pixel XL Also Crashes on iOS ...
Scene Color node with UV input on a transparent material renders incorrectly in stereo
UE - Platform - XR - Jan 19, 2021From Licensee: When we have Instanced Stereo enabled, all our materials that use Scene expression nodes (SceneDepth, SceneColor, etc...), render incorrectly in the right eye. It only happens to the ...
Possible incorrect pointer manipulation in BeginPackageCacheForCookedPlatformData
UE - Foundation - Core - Cooker - Dec 12, 2017In UCookOnTheFlyServer::BeginPackageCacheForCookedPlatformData(), there is a pointer to int32 called CurrentAsyncCache that is used as an index. It's value is dereferenced before it is checked, but ...
Crash when a floor mesh is removed while a Vehicle has SimulatePhysics disabled
UE - Runtime - Simulation - Sep 1, 2026When SimulatePhysics is disabled, the constraint update is skipped, so a reference to an invalid (already-removed) particle is left behind. As a workaround, the approach suggested by the licensee — ...
Exporting Mannequin to Blender then Re-importing to UE4 Incorrectly Rotates Animations by 90 Degrees
OLD - Anim - Jun 16, 2015Exporting the UE4 Mannequin to Blender then re-importing to UE4 breaks the animations, causing them to reimport rotated 90 degrees ...