Adding a New Blackboard Key While Searching for a Blackboard Key Causes the Editor to Crash

UE - AI - Nov 12, 2015

When you use the search bar located under the New Key button in a Blackboard asset, if you attempt to press New Key while you have text in the search field, the editor will crash after you select th ...

When a Niagara System has SimTarget set to GPUCompute Sim, CameraQuery is only returning data from the Player0 camera, ignoring the PlayerControllerIndex.

UE - Niagara - Nov 8, 2024

When a Niagara System has SimTarget set to GPUCompute Sim, CameraQuery is only returning data from the Player0 camera, regardless of PlayerControllerIndex. The expected behavior would be to have the ...

Crash when opening a texture or editing its properties after stopping a preview in the material editor

UE - Rendering Architecture - Materials - Sep 5, 2025

When a texture asset has certain properties edited, its PostEditChangeProperty() method calls to UTexture::NotifyMaterials(), which triggers a recompilation of materials that reference it in their m ...

[CrashReport] Mac crash - UE4Game!FShaderCache::InternalSetGraphicsPipelineState

UE - Graphics Features - Dec 1, 2017

This is a common Mac crash in 4.18. It occurs in Game mode, not in Editor. Users have not provided any descriptions of their actions when the crash occurred. Callstack from Log[2017.11.21-20.30.4 ...

[Stream Cache][Assert] - UnrealEditor_Engine!FCachedAudioStreamingManager::RemoveReferenceToChunk() [AudioStreamingCache.cpp:701]

UE - Audio - Stream Caching - Mar 12, 2024

Found while messing around with a revamp of some of the Audio Stream cache tests. The map in this test is a WIP as I'm still just trying stuff out, but hit this assert 5/5 times.Assertion failed: Fo ...

Crash in RHICommandContext& GetContext() in Test/Shipping builds when bUseChecksInShipping is true

UE - Rendering Architecture - RHI - Nov 29, 2022

RHIinit() calls GRHICommandList.GetImmediateCommandList().GetContext() to make sure that GDynamicRHI->Init() initialized the immediate command list (by calling FRHICommandListImmediate::InitializeIm ...

Behavior Tree (BT) services added to root nodes call the initial tick twice

UE - AI - Nov 20, 2024

Behavior Tree (BT) services added to root nodes call the initial tick twice A BT Service with the setting "Call Tick on Search Start" enabled will execute the initial tick twice when added to the ro ...

FNiagaraScalabilityManager incorrectly reactivates a NiagaraComponent that was deactivated by runtime user code

UE - Niagara - Scalability - Oct 1, 2025

Context: The Niagara System is the primary tool to do visual effects inside Unreal. Niagara systems can be culled due to distance. Problem: Once a deactivated Niagara System is culled due to distan ...

Bloated instruction counts in the material editor causing long compiles

UE - Graphics Features - Apr 17, 2019

artists are dealing with greatly increased iteration times due to long shader compiles when working in the material editor. This has regressed over time as we add more features to the point were wor ...

Reversed Animations don't play properly using Skeletal Mesh Pose and animations with Keep State in Sequencer

UE - Anim - Sequencer - Nov 26, 2018

The bug seems to only reproduce when setting animations in sequencer and only if the animations are set to "Keep state". Setting them to "restore default" makes the reversed animation play correctly ...