Crash when using the Blueprint merge tool

UE - Gameplay - Blueprint Editor - Apr 26, 2021

The Editor crashes when merging a change using the Blueprint Merge tool on Linux.  ...

Duplicating / Moving (to another level) an actor with a Hierarchical Instanced Static Mesh component causes a crash

UE - Graphics Features - Nov 14, 2016

When you have an actor with a Hierarchical Instanced Static Mesh component that has a Static Mesh set and is populated with at least 1 instance and then duplicate it or move it to another level, it ...

Bake To Control Rig on a Spawned Actor in a Subsequence with Play Range that exceeds the Subsequence causes a Crash

UE - Anim - Anim in Engine - Jun 28, 2023

This is a Regression. Tested in //UE5/Release-5.1 CL23901901 Using Bake To Control Rig on a Spawned Actor in a Subsequence with Play Range that exceeds the Subsequence causes a Crash. ...

BP - Nativization will fail at cook time if a BP class and a User-Defined Structure reference each other.

UE - Gameplay - Blueprint - Apr 20, 2017

Note: This happens with "Exclusive" nativization mode as well. This occurs because the nativized UDS 'GetDefaultValue()' method is generated into a .h file rather than a .cpp file. This creates a c ...

Crash launching UE4Editor.exe from cmd.exe with -dx12 argument

UE - Graphics Features - Feb 3, 2017

My Nvidia driver is our current approved driver: 378.49 ...

In Packaged builds, Chaos Cache Manager can't animate Geometry Collections with Nanite Enabled if Cache Mode is set to Static Pose

UE - Simulation - Physics - Destruction - Feb 27, 2025

In Packaged builds, Chaos Cache Manager (CCM) can't animate Geometry Collections (GC) with Nanite Enabled if Cache Mode is set to Static Pose. The licensee tried to animate a CCM using Sequencer onl ...

MDL imported from Substance Source with Datasmith causes a crash

UE - Editor - Content Pipeline - Import and Export - Mar 8, 2019

MDL downloaded from Substance Source causes a crash. This is reported on UDN by an Enterprise customer: https://udn.unrealengine.com/questions/487598/why-would-ue4-is-always-crashing-when-import ...

FAnimationRuntime::BlendPosesPerBoneFilter() causes an assertive crash when Skeletal Mesh LOD is changed

UE - Anim - Runtime - Nov 1, 2023

The crash occurs from "check(BoneBlendWeights.Num() == NumBones);" This crash occurs when the following conditions are met;The skeletal mesh LOD is changed.The number of bones is difference between ...

Creating a control rig via FControlRigBlueprintActions::CreateNewControlRigAsset crashes

UE - Anim - Rigging - Control Rig - Nov 10, 2023

FControlRigBlueprintActions::CreateNewControlRigAsset is crashing in ResolveObjectHandleNoRead.  Looking at the control rig in UControlRigBlueprint::Serialize, it's marked as pendingkill but I'm uns ...

Crash when generating proxy mesh

Tools - Jul 12, 2019

Generating a proxy mesh with imported models and the simplify mesh flag set to true causes the editor to crash. Tested in 4.21.2 (CL - 4753647), 4.22.3 (CL - 7053647), 4.23 (CL - 7288428), 4.24 (CL ...