Unreal Engine Issues
Unreal Engine Issues
Material Parameters aren't unique if the Material Function has been duplicated
UE - Graphics Features - Jul 31, 2017Material Parameters aren't unique if the Material Functions has been duplicated, When the parameters are enabled in a Material Instance, one will be disabled on Material Instance close. This is a r ...
[CrashReport] ULevel::GetWorldSettings - UStaticMeshThumbnailRenderer::Draw
Tools - Oct 30, 2017This is a common crash that has occurred since at least 4.14. The callstack is nearly identical to [Link Removed], which appears to be fixed in 4.18; and [Link Removed], which has not. The differen ...
Volumetric fog does play nice with dynamic res
UE - Graphics Features - Jan 4, 2019Dynamic resolution dynamically changes the the size of the viewport in render targets. The thing is when the resolution changes: it is reprojecting previous frame that is stored in history render ta ...
Asset localization does not work properly for Paper2D related assets such as Flipbook
UE - Foundation - Mar 18, 2022This issue is resolved by changing Paper2D's LoadingPhase to PostConfigInit, but this is a workaround. We suggest a better long term fix via AssetRegistry changes (see comments). In the default la ...
Pose watches don't display correctly with compatible skeletons
UE - Anim - Runtime - Anim Blueprints - Aug 19, 2022"Hello, we've found a quirk with ABP's pose watch and compatible skeletons. Same setup as above. We have skeleton A as the base and skeleton B as a compatible skeleton. They both share similar hiera ...
Iris - large fast arrays serialize multiple elements when only one is dirtied
UE - Networking - Iris - Apr 8, 2025This seems to be a result of how the changemask is handled for fast arrays. Because the changemask is a fixed set of bits (defined by IrisFastArrayChangeMaskBits), a single bit can represent multipl ...
The hierarchy of Actors in LevelInstances can break when using BPs as parent
UE - World Creation - Worldbuilding Tools - Level Instances - Feb 18, 2026The hierarchy of a LevelInstance actors (Outliner) will break when cooking. The source is the call to AActor::RerunConstructionScripts in FWorldPartitionLevelHelper::MoveExternalActorsToLevel. The ...
When typing Korean in Slate using FTextInputMethodContext, characters outside a specific range are not entered
UE - Editor - UI Systems - Slate - Apr 7, 2026Descriptions After getting the below message LogTextStoreACP: Verbose: GetTextExt - From 33 to 34 A line break past that range is inserted. However, when typing Korean, the correct range is not s ...
Crash when adding multiple collision types to a mesh
Tools - Jan 27, 2017Adding various collision types to a single mesh will cause it to hard crash the editor. No Crash Reporter window will open. Note that this happens with the user's mesh, but I was not able to repro ...
USkinnedMeshComponent::FindClosestBone does not respect bRequirePhysicsAsset parameter
OLD - Anim - Mar 20, 2017A licensee has reported that the USkinnedMeshComponent::FindClosestBone function does not respect the bRequiresPhysicsAsset parameter, resulting in the bone returning bones that are not part of the ...