Unreal Engine Issues
Unreal Engine Issues
BlendSpace Loop Boundary Produces Inconsistent Sync Marker Data andTriggers an AnimSequence Follower Assertion
UE - Runtime - Animation - Jul 22, 2026Summary In UE 5.7.4, when a looping BlendSpace with Match Sync Phases enabled plays as a SyncGroup Leader and crosses its loop boundary during a transition to an external AnimSequenceFollower in th ...
Precomputed AO Mask renders with value of zero after building lighting
UE - Rendering - Architecture - Materials - Jan 13, 2023Regression: Tested in UE5/Release-5.0 at CL 20979098, this issue does not occur so it is a regression. This issue occurs in 5.1 for both normal light building and GPU Lightmass building. In 5.0 th ...
Parameter metadata not accessible if modified in Material Instance and then converted to CustomPrimitiveData
UE - Rendering - Architecture - Materials - Jun 24, 2026There’s a potential issue with some changes we made to UMaterialInstance::GetParameterValue (https://github.com/EpicGames/UnrealEngine/commit/8f2bebb008ba645f5938da844cd46b0925322b13). It seems as t ...
Editing an instanced variable that is nested in two other instanced variables causes a crash
UE - Gameplay - Blueprint - Jul 2, 2015If a user edits a instanced variable which is nested inside two other instanced variables in blueprint editor, a crash will occur ...
GPU Timeout when using a large scale Landscape and Water Body Ocean
UE - Graphics Tools - Terrain - Landscape - Dec 1, 2022Regression: Tested in //UE5/Release-5.0, this issue does not occur so regression is yes. The GPU Timeout only occurs in UE5/Release-5.1, as recreating this issue in previous versions of the editor ...
Niagara Parameters window resets when clicking in a Scratch Module
UE - Rendering - Architecture - Niagara - Nov 29, 2022Regression: The UI for the Parameters window in a Niagara System is different from UE5/Release-5.0 to UE5/Release-5.1, so the issue cannot be replicated in Release-5.0 This issue occurs when going ...
Mesh from attached USD fails to import
UE - Editor - Content Pipeline - USD - Mar 31, 2025UDN customer reported this issue: Using legacy USDImporter, the attached USD throws these ensures ensure(Primvar.Get(&UVs, Options.TimeCode)); ensure(Primvar.GetIndices(&Indices, Options.TimeCode) ...
Hovering items at bottom right of Content Browser does not display tooltip and causes cursor flicker
UE - Editor - Sep 17, 2025When hovering over items located at the bottom right corner of the Content Browser while the Editor is maximized, the tooltip is not displayed. It seems that the tooltip would extend beyond the edge ...
USD Stage Import - Spawned actors by USD importer are not saved in level
UE - Editor - Content Pipeline - USD - Jul 20, 2023we ran into an issue with USD Importer plugin for Unreal 5.2. When you import a USDStage with the "actors" import option - which respawns the newly imported actors into the current level. However, ...
Widget components and widgets in screen space are not the same color
UE - Editor - UI Systems - Jun 27, 2016Widget components appear to be affected by lighting. This causes differences in color between widget components and widgets that have been added to the viewport. ...