Unreal Engine Issues
Unreal Engine Issues
Section::TrimSection resulting in bad key values at start and end of trim range
UE - Anim - Sequencer - Dec 17, 2025The trim process inserts keys at the start or end of the range depending if you specify Trim Left or Right, I'm finding that Trim right is inserting a key at the end of the section that is incorrect ...
ActorComponents registered with wrong world from UWorldPartition::ApplyRuntimeCellsTransformerStack
UE - World Creation - Worldbuilding Tools - World Partition - Dec 17, 2025There is a risk of actor components registering with the wrong world when reconstructed from UWorldPartition::ApplyRuntimeCellsTransformerStack. The repro case is arguably a bad usage, but it was th ...
Viewport stuttering during orbit/zoom navigation
UE - Graphics Features - Dec 17, 2025Received a report of persistent stutters in the editor when trying to navigate in the viewport, including asset editor viewports like the Skeletal mesh editor and control rig editor. Hardware used ...
A chaos vehicle that moves at very high speeds with CCD enabled on the vehicle sometimes has a collision response that is abnormal where the vehicle loses a significant amount of speed when colliding with dynamic objects configured as One Way Interaction
UE - Simulation - Gameplay - Dec 16, 2025Context: Continuous Collision Detection (CCD) is being used on a Chaos Vehicle to avoid tunneling issues with certain surfaces as it prevents any missed collisions between fast moving particles and ...
ISM Cell Transformer breaks component hierarchy when child component are transformed
UE - World Creation - Worldbuilding Tools - World Partition - Dec 15, 2025This case is related to [Link Removed] but is not a duplicate. Please make sure to download the attached project as it's different than the one in the other case. The problem here is that the ...
Automated tests DynamicSubobjectInstancing and NonNativeInstancedSubobjects (CoreUObject group) fail
UE - Framework - Dec 15, 2025The DynamicSubobjectInstancing and NonNativeInstancedSubobjects automation tests fail. ...
[AI] StateTree fails to compile after copy/pasting a state with a task that binds to required event on the state's enter conditions
UE - AI - StateTree - Dec 14, 2025StateTree appears to keep an incorrect reference to the event from the source tree rather than re-establishing the property binding to the new tree's event. This happens when copy/paste of the state ...
OcclusionFeedback may not be performant for primitives with large screensize
UE - Platform - Mobile - Dec 13, 2025A licensee reported that the performance could be worse in some scenarios (probably a small scene with large objects) with OcclusionFeedback enabled ( 20fps up if disabled), tested on a Qualcomm 870 ...
FormatName is not added to the display name of gpu events in some cases.
UE - Foundation - Insights - Dec 12, 2025If the breadcrumb events have no metadata but the metadata spec contains a format name, the format name is not added to the display name and the user cannot see it. GPU Profiler 2.0. The trace they ...
Iris - Ensure hit when destroying a torn off actor from AActor::TornOff
UE - Networking - Iris - Dec 11, 2025As of CL 42014318, StopReplication requests that occur during ReceiveUpdate are delayed until all received data from the update is finished processing, including if the actor is torn off. However, i ...