Editor Crashes When Using Set Replicates in the Construction Script

UE - Networking - Mar 1, 2016

When spawning an actor using the Spawn Actor From Class node that has a Set Replicates node in the construction script, the editor crashes upon attempting to run a dedicated server with 2 players. ...

[CrashReport] UE4Editor_Engine!FPhysScene::SyncComponentsToBodies_AssumesLocked() [physscene.cpp:1271]

UE - Simulation - Physics - Dec 1, 2017

This is a common crash in 4.18 and 4.18.1. The callstack shares similarities to [Link Removed], although that has been confirmed fixed in 4.18. Included in the same crashGroup are also a few Ensur ...

Crash when enabling dynamic branch on static switches in Post Process Materials

UE - Rendering - Architecture - Materials - Jun 28, 2023

[Link Removed] Some functions to access parameters don't take into account the newly added runtime static switch parameters. It should be straightforward to fix these up: void UMaterialInstance:: ...

Starter Content Blueprint_Effect_Explosion Root Componet In Invalid State

UE - Content - Feature Pack - Sep 22, 2023

The Blueprint_Effect_Explosion Actor's Root Component in the Starter Content is in some form of invalid state. It reports to have a scale of (1.0, 1.0, 1.0) in the details panel but further behaviou ...

Editor Crashes When Reparenting a Trigger Sphere to a Trigger Capsule

UE - Simulation - Physics - Aug 15, 2016

Reparenting a blueprint derived from Trigger Sphere to Trigger Capsule will cause the editor to crash. This is a regression. This did not occur in 4.11.2. Source Context: 163 164 ...

In 5.6, bWarningsAsErrors does not work with clang

UE - Foundation - Cpp Tools - UnrealBuildTool - Sep 20, 2025

In 5.6, many warnings and errors specify their command line arguments to the compiler with these new C# attributes:    [WarningsClangToolChain(["-Wno-date-time"], ["-Wdate-time", "-Wno-error=date-ti ...

Instanced Actors: PCG on RuntimeGrid "None" assigns created IAManagers RuntimeGrid "MainGrid", causing cross-grid reference

UE - World Creation - Procedural Tools - PCG Graph - May 30, 2026

Context PCG can be used to spawn Instanced Actors via the PCG IA Interop plugin, that makes Spawned Instanced Actors available as node. When a PCGActor placed in the level runs a PCG graph that spa ...

MaterialTextureScale calculated incorrectly for materials with WorldPositionOffset

UE - Rendering - Architecture - Materials - Apr 16, 2024

When a Material uses WorldPositionOffset, the MaterialTextureScale is calculated incorrectly because FMaterialUtilities::ExportMaterialUVDensities() calls FMeshRenderer::RenderMaterialTexCoordScales ...

Using a FormatText node with Specifier in the same graph as an empty Macro will freeze the editor

UE - Gameplay - Blueprint - Jun 17, 2016

Using a FormatText node with Specifier in the same graph as an empty Macro will freeze the editor. Not using the Specifier or deleting the unused Marco will allow the BP to compile fine. **Only rep ...

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 ...