LevelEditor: "Replace Actor" marks level as dirty even when using external actors

UE - World Creation - Worldbuilding Tools - Jul 15, 2024

When using external actors, adding/removing/replacing/editing an actor instance inside a level does not cause any modification to the Level package, which helps reduce contention for the map file on ...

ISM + WPO = broken motion vectors?

UE - Graphics Features - Nov 5, 2024

Instanced Static Meshes will have incorrect velocity if a Material uses World Position Offset. Fixed WPO in a material causes significant velocity on the ISM. This was also replicated in //UE5/Rele ...

ForEachLoop does not save structure changes in the loop body

UE - Gameplay - Blueprint - Feb 2, 2015

If a ForEachLoop node is used to cycle through an Array of Structures, using the Array Element output of the Loop node to set the members of the structure does not save the changed values. Workarou ...

Landscape Visibility Mask Rendering with Missing Landscape Components when Deployed to Mobile Device

UE - Graphics Features - Apr 8, 2015

Landscape Material renders with missing components when using a 'Landscape Visibility Mask' and deploying to a mobile device. I have found this issue now with an Android and iOS device. I was able ...

Camera jitter when using Crane Rig with Look At

UE - Anim - Sequencer - Jul 21, 2016

Camera jitter when using Crane Rig with a Cine Camera that is using the Look At Functionality ...

[CrashReport] UE4Editor_Slate!TAttribute<FText>::Get() [attribute.h:130]

UE - Editor - UI Systems - Slate - Jul 13, 2017

This is a common crash affecting users in 4.16 User DescriptionsI imported an FBX and the editor crashed.alembic import from brekelwhats wrong with the ue4 alembic importer? Source Context 120 ...

Default values specified for local BP variables of type DateTime and Timespan don't actually work

UE - Gameplay - Blueprint Runtime - Nov 6, 2020

Have attached examples of this in action, including breakpoints showing the FDateTime::Ticks count as zero. Also showed that this is an issue for the existing GetYear/GetMonth/GetDay methods (and an ...

Crash when exposing a TOptional<FName> or TOptional<FText> to the editor through a UProperty.

UE - Editor - Workflow Systems - Mar 25, 2025

Support for editor-exposed uproperties of type TOptional<T> has been added by CL 28199740 on september 2023. However, since then until today in UE 5.5, a crash can happen when exposing TOptional<FNa ...

Adding new elements to an array in code does not update in a class based blueprint on compile

UE - Gameplay - Blueprint - May 5, 2015

When adding elements to an array inside a code class, blueprint instances of the class do not have their array updated after a hot reload. ...

Collision outcome is different between PIE and Mobile Preview/Packaged Project.

UE - Simulation - Physics - Mar 25, 2015

When playing the user's project in editor vs Packaged, there has been different results for the enemies collision. When playing in PIE, you are able to fly through the enemies with no issues. When p ...