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 ...

[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 ...

Instance static mesh instances are reset to zero when moving actor between levels (via move actor to current level)

Tools - Nov 13, 2018

When moving an instance static mesh between sublevels the number of instances being used will be set to zero. This happens when an empty actor is added to the level and then has an instance static m ...

[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 ...

Once an actor channel is closed by NetCullDistance, root motion movement synchronization stops working

UE - Networking - Jul 12, 2021

Properties that uses DOREPLIFETIME_ACTIVE_OVERRIDE (ex. RepRootMotion ) will also skip replication when an actor channel is newly opened. This means that if the variables on the server side do not c ...

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 ...

D3D HUNG crash with Aftermath result: CullLights

UE - Graphics Features - Apr 27, 2017

This is a specific subset of D3D HUNG crashes from [Link Removed]. This JIRA is for the crashes with the following results from Aftermath: [105]LogRHI:Error: [Aftermath] Status: Timeout [105]LogR ...