Crash When Copying Comment Box from a Blueprint to a Behavior Tree

UE - AI - Jun 8, 2016

The editor crashes when pasting a comment box from a blueprint into a behavior tree. Found in 4.12.1 binary. Reproduced in 4.11.2 binary and Main CL 3005971 Source Context94 95 fo ...

Internal Compile error received from rearranging Format Text nodes

UE - Gameplay - Blueprint - Dec 18, 2014

Internal Compile error received from rearranging Format Text nodes Output Log of Error: LogBlueprint:Error: [compiler] Error Internal compiler error inside CreateExecutionSchedule (site 2); please ...

[CrashReport] UE4Editor_Engine!FDistanceFieldAsyncQueue::Build()

UE - Graphics Features - Jul 24, 2017

This is a common crash callstack that has affected more than 300 unique users since at least the 4.11 release. Other Jiras in the past with similar callstacks include [Link Removed] and [Link Remo ...

Crash Importing Skeletal Mesh LODs with a lot of morph targets

OLD - Anim - May 18, 2016

Crash Importing Skeletal Mesh LODs with a lot of morph targets Error message: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 785] Array index out of bounds: 2 from an ar ...

When using Perforce, saving a level over another leaves the target umap file as "marked for delete"

UE - Editor - Mar 11, 2025

When working on a level asset and using command "File – Save Current Level As..." to save it over a different level asset, the engine first deletes the target level (that's going to be overwritten) ...

[CrashReport] Assertion failed: TaskDataArray.Num() == Exporter->VolumetricLightmapTaskGuids.Num()

UE - Graphics Features - Lumen - Oct 2, 2017

This is a trending crash coming out of the 4.18 Previews. Users have not provided any descriptions of their actions when the crash occurred, but at least two of the affected projects are being creat ...

[5.4+] World Partition Landscape Spline Meshes Builder - Source landscape splines are not properly removed/hidden

UE - Engine Scaling - Streaming - HLOD - May 30, 2025

LandscapeSplineActors and LandscapeSplineMeshesActors are not behaving as expected in 5.4 or 5.5. Testing in 5.4 the issue mostly seems to stem from issues with the Target Landscape -> Landscape Ac ...

5.5 Static Mesh Import Pipeline Regression

zComponent - Archive - Apr 25, 2025

This question was created in reference to: [Link Removed] This post references the first post because this problem was not discovered till now. I think it was masked because the issue appears to be ...

Controller input changes for network players based on which window has focus

UE - Gameplay - Input - May 23, 2016

When testing networked multiplayer with two controllers, if the server window (editor) has focus, controller 1 controls the server character and controller 2 controls the client character. If the c ...

Editor crashes due to a material that contains MPCs migrated from another project

UE - Rendering - Architecture - Materials - Apr 29, 2024

[2024.04.29-16.49.46:563][970]LogUObjectGlobals: Warning: LoadPackage can't find package /BEURRE_040824_041224/NewMaterialParameterCollection. [2024.04.29-16.49.46:563][970]LogUObjectGlobals: Warning ...