Mirror Data Table is NOT added SyncMarker automatically when creating

UE - Anim - Runtime - Oct 27, 2022

Mirror Data Table is added rows about Bone, Curve, Notify when creating. But SyncMarker is ignored. The following codes can fix this issue. Engine/Source/Runtime/Engine/Private/Animation/MirrorDa ...

Delta struct serialized fast arrays replicating new elements with no changelist

UE - Networking - Jun 14, 2021

There is a scenario where delta struct serialized fast arrays can replicate changes that introduce additional elements to the array, but without changelists containing the new data. This needs furt ...

Crash after clearing the animation from a sample point in a 1D Blendspace

OLD - Anim - Mar 8, 2017

Regression: YES, sort of. The ability to change the animation from a dropdown didn't exist in 4.14 Error message: Fatal error: [Link Removed] [Line: 160] Ran out of memory allocating 51539607528 ...

PCG: Unable to use Attribute property overrides to target nested struct properties, such as BodyInstance.CollisionProfileName due to how it's validated in PCGMeshSelectorByAttribute.cpp

UE - World Creation - Procedural Tools - PCG Workflow - Jun 17, 2025

Context: Static Mesh Spawner is used to spawn one static mesh per point in the provided point data. PCGMeshSelectorByAttribute is used to select an entry based on an attribute present on the mesh. ...

Once an actor channel is closed by NetCullDistance, root motion movement synchronization stops working

UE - Networking - Jul 12, 2021

Properties that uses DOREPLIFETIME_ACTIVE_OVERRIDE (ex. RepRootMotion ) will also skip replication when an actor channel is newly opened. This means that if the variables on the server side do not c ...

AreaNavModifiers generated by SplineNavModifierComponent have the component-to-world transform incorrectly applied twice

UE - AI - Navigation - Aug 15, 2025

USplineNavModifierComponent was made available in UE 5.4. It generates several FAreaNavModifier instances covering a region with a certain thickness around a USplineComponent, and worked correctly u ...

Available network bandwidth is too low for uncapped but slow frame rates

UE - Networking - Sep 24, 2020

The networking system has a max frame rate of 120hz by default. Inside UNetConnection::Tick it computes an estimated bandwidth by using that max frame rate, the engine's max frame rate, and the actu ...

[CrashReport] FSlateRHIRenderer::ConditionalResizeViewport()

Tools - Jul 27, 2017

This is a common crash occurring on Windows and Mac in 4.15 and 4.16 (two different callstacks with close similarities). The callstack is also similar to [Link Removed] and may be related. User D ...

CPF_TextExportTransient and RF_TextExportTransient inconsistent behavior

UE - Framework - Blueprint - May 23, 2024

The TextExportTransient can be specified as a property flag and object flag. Behavior is inconsistent: there are many ways in which an object marked TextExportTransient can still be part of the text ...

Branching Points in a Montage Affect the Rotation Outcome of Root Motion

UE - Anim - Runtime - Mar 28, 2025

When playing Montages with Root Motion, the sub stepper extracts root motion transform in small increments. If a Branching Point exists within the interval being extracted, the extraction range is s ...