WP level instance runtime settings affect streaming generation

UE - World Creation - Worldbuilding Tools - World Partition - Nov 16, 2023

If a level instance uses different runtime settings then it can override the main WP's runtime settings with UWorldPartitionRuntimeSpatialHash::ApplyCVars Runtime settings:GRuntimeSpatialHashUseA ...

Level Streaming - Always Loaded sublevel affected by streaming volumes

UE - World Creation - Worldbuilding Tools - Mar 19, 2024

The docs mention: "When a streaming Level is set to Always Loaded, it is loaded together with the persistent Level. It also becomes visible at the same time as the persistent Level. It ignores strea ...

Branching Points in a Montage Affect the Rotation Outcome of Root Motion

UE - Anim - Runtime - Mar 28, 2025

When playing Montages with Root Motion, the sub stepper extracts root motion transform in small increments. If a Branching Point exists within the interval being extracted, the extraction range is s ...

SetGamePause does not affect Sequencer pause if using audio clock as source

UE - Audio - Sequencer - Oct 24, 2025

We’ve run into some unexpected behavior when combining SetGamePause(true) with Level Sequences. When calling SetGamePause(true) while a Level Sequence is playing, the visuals pause correctly, b ...

[CrashReport] UE4Editor_Engine!UAnimMontage::IsValidAdditive() [animmontage.cpp:702]

OLD - Anim - May 19, 2016

Error message: Stack overflow - code c00000fd (first/second chance not available) Source Context: 687 if (SyncGroup != NAME_None) 688 { 689 CollectMarkers(); 690 ...

Crash occurs when renaming an asset that is used by Class Default Object

UE - CoreTech - UObject - Nov 23, 2021

Not a regression. Tested in: //UE4/Release-4.26.2 CL15973114 Binary - Reproduced //UE4/Release-4.27.1 CL17735300 Binary - Reproduced //UE5/Release-5.0-EarlyAccess CL16682836 Binary - Reproduced Fro ...

Crash upon diffing Blueprint that was reparented when its previous parent has already been deleted

UE - Gameplay - Blueprint Editor - Sep 20, 2017

When attempting to diff a Blueprint that has been reparented when the previous parent no longer exists in the editor, a crash occurs. The crash is due to the editor attempting to reference the delet ...

LayeredBlendPerBone with BlendRootMotionBasedOnRootBone set incorrectly calculates root motion weightings with more than two sources

UE - Anim - Runtime - May 27, 2023

When BlendRootMotionBasedOnRootBone is true, the code in  FAnimNode_LayeredBoneBlend::Update_AnyThread that calculates the root motion weightings for the sources doesn't appear to account for the po ...

[CrashReport] UE4Editor_UnrealEd!UnFbx::FFbxImporter::RecursiveBuildSkeleton()

UE - Editor - Content Pipeline - Import and Export - Jul 30, 2015

This is a common crash affecting users. User DescriptionsJust import a Mesh of Fuse Source Context 624 void UnFbx::FFbxImporter::RecursiveBuildSkeleton(FbxNode* Link, TArray<FbxNode*>& Out ...

[CrashReport] UE4Editor_Sequencer!FSequencer::NotifyMovieSceneDataChanged()

UE - Anim - Sequencer - Jul 24, 2017

This is a common crash affecting users in 4.16 and into the 4.17 Preview. User Descriptionscopying-pasting curves in Sequencer Source Context 979 void FSequencer::NotifyMovieSceneDataCha ...