World Partition - Deleted actors can become unloaded prior to saving

UE - World Creation - Worldbuilding Tools - World Partition - Apr 11, 2025

In world partition levels, deleted actors can become unexpectedly unloaded prior to saving, causing loss of work. Specifically, this issue occurs after the undo history has been cleared (either manu ...

Incorrect Velocity Calculation at Animation Sequence Transitions in Level Sequence

UE - Anim - Sequencer - Feb 18, 2025

When adding an Animation Track to a Level Sequence and placing Animation Sequences back-to-back without gaps, the velocity can be miscalculated at the transition between sequences. This issue occur ...

Unable to edit double variable in property matrix

UE - Editor - Workflow Systems - Oct 2, 2023

Since UE5.0, cannot edit double variables in property matrix. In UE4.27, it worked correctly and could be edited from the property matrix. This is because double variables are not supported in SProp ...

SpringArmComponent with "Use Camera Lag Substepping" does not handle fluctuating frame rates correctly

UE - Gameplay - Jun 4, 2024

The description of SpringArmComponent's "Use Camera Lag Substepping" option says "sub-step camera damping so that it handles fluctuating frame rates well". However, as noted and explained by a licen ...

[CrashReport] Assertion failed: !bRequireNormalization - UE4Editor_Landscape!ULandscapeComponent::ReplaceLayer()

UE - LD & Modeling - Terrain - Landscape - Jul 19, 2017

This is a common crash affecting users in 4.16, and has occurred since at least 4.14. Over 200 unique users have been affected, though they have provided little information. User DescriptionsI am a ...

Incorrect behavior after attaching an actor to a non-root component of another actor in the Editor

UE - Editor - Workflow Systems - Jul 3, 2024

UE allows actors to be attached to other actors. More precisely, it allows the root component of an actor (child) to be attached to any component of another actor (parent). From now on, "parent" and ...

[CrashReport] UE4Editor-CoreUObject.dylib!UObject::Rename()

UE - Platform - Apple - Sep 14, 2017

This is an infrequent Mac crash that has occurred for a few users in 4.17. Users have not provided any description of their actions when the crash occurred. The callstack has a few similarities to ...

[CrashReport] UEdGraphSchema_K2::PinHasSplittableStructType

UE - Gameplay - Blueprint - Sep 14, 2017

This crash is affecting a few users in 4.17. ...

Niagara Emitter editor forgets Timeline playback ranges

UE - Niagara - Sep 14, 2020

This seems to only affect an emitter and not a system asset. ...

Allowed Material Slots in the Sample Static Mesh module is not working properly.

UE - Niagara - Jun 24, 2022

It is behaving correctly in 4.27.2. ...