Translucent User Interface materials do not have a thumbnail preview

Tools - Feb 15, 2018

Translucent User Interface materials do not have a thumbnail preview. I do not see this issue with Translucent Surface materials. REGRESSION: No, this issue also occurs as far back as 4.17.2 ...

[AI] Nav Modifier Volume inside of a Level Instance does not update navmesh when moved

UE - Runtime - Character - Oct 3, 2023

The issue is seen when using a normal navmesh inside of a World Partitioned level. Adding a Nav Modifier Volume to a Level Instance, and placing the Level Instance in the world will affect the navme ...

Soft Object unloads after some time when stored in a Blackboard

UE - AI - Mar 11, 2020

When loading a Soft Object and directly placing the loaded Object into a Blackboard, after about 2 minutes the Object will unload and become null inside the Blackboard. This issue only occurs in a p ...

BSP brushes get Clipped or Disappear relative to the Surface Normals of a nearby Brush when Deleting/Flipping Faces

UE - LD & Modeling - Modeling Tools - BSP - May 1, 2017

While testing this issue it was interesting to discover how the surrounding BSP's were affected. They seemed to clip/disappear according to the surface normals of the deleted brushes. There is a si ...

Ensure starting PIE after editing character blueprint of a code based side scrollers

UE - Gameplay - Apr 6, 2016

After editing character blueprint of a code based side scroller project, starting PIE will show the camera detached from the character and exiting PIE causes the project to crash. NOTE: This appear ...

Incorrect WorldType causes crash in ULandscapeSplinesComponent::CheckForErrors

UE - LD & Modeling - Terrain - Landscape - Jun 21, 2018

When adding a sub-level that contains a Landscape and Landscape Splines to an existing Level, it will cause a crash when building the lighting.  This issue was reported in 4.18.3 (CL 3832480) and t ...

Scroll Bar does not Stay "Anchored" to Bottom While Data Generates in Window

Tools - Jun 6, 2016

The scrollbar no longer remains anchored to the bottom of the Output Log while more lines are propagated during the packaging process/ Regression: this does not occur in previous versions of the En ...

SKP import - Materials missing and incorrect when using Collapse all

TM - Interoperability - Sep 30, 2026

Reported in SF [Link Removed] When importing a .skp model into Twinmotion 2026.2 Preview as Geoemtry, using the Collapse all mode will cause materials to be displayed incorrectly, replacing most ma ...

Incorrect config property serialization for UStructs used as TMap keys or contained in a TSet with a single value. Diffs taken from default-value of each member type, instead of from default-value of the struct

UE - Core - Systems - Nov 18, 2024

Consider a UStruct with some basic type members, each one with a default value specified in the struct. Also consider a TSet or TMap with that struct as keys, used inside a UObject as a UProperty an ...

Investigate crash with replication nested ever changing attachments

UE - Framework - Networking - May 7, 2024

There seems to be an issue with replicated attachments ending up causing cyclical setups resulting in crash on clients. It was reported for 5.2 but even after patching up code it seems to occur. ...