Unreal Engine Issues
Unreal Engine Issues
Wrong calculation of "MaxAllocatedCountEstimate" inside FNiagaraRendererRibbons::GenerateDynamicData()
UE - Niagara - Mar 20, 2026Starting with UE 5.4, function FNiagaraRendererRibbons::GenerateDynamicData() from file [NiagaraRendererRibbons.cpp] attempts to calculate DynamicData->MaxAllocatedCountEstimate as such: DynamicDat ...
Crash when Live Coding is triggered after engine source edits Blueprints using ChildActorComponent
UE - Framework - Blueprint - Nov 28, 2025After editing engine source files and triggering Live Coding, derived Blueprints that inherit from a Blueprint containing a ChildActorComponent cause UChildActorComponent::Serialize to run on a Live ...
Preview Rendering Levels Do Not Display Supported Optimization Viewmodes in Viewport Dropdown
UE - Platform - Mobile - Apr 2, 2019When attempting to set an optimization viewmode while using a Preview Rendering Level other than Shader Model 5, the Optimization Viewmodes dropdown is missing all of its options and instead display ...
Editor Crashes when copying/pasting a custom event function that was within a separate function to an event graph if the custom event was created in another blueprint
UE - Gameplay - Blueprint - Jan 16, 2015Editor crashes when a custom event node is called as a function within a different blueprint in a separate function, then copied and pasted into the event graph of the second blueprint, the executio ...
Crash when using "Convert to Variable Curve"
OLD - Anim - Jun 7, 2016Error message: Access violation - code c0000005 (first/second chance not available) Source Context: 7 8 DECLARE_CYCLE_STAT(TEXT("AnimSeq EvalCurveData"), STAT_AnimSeq_EvalCurv ...
Assertion occurs when undoing a Child State's unparenting from another Child State in AI State Trees, leading to a crash.
UE - AI - StateTree - Apr 15, 2022Assertion occurs when undoing a Child State's unparenting from another Child State. Repro Rate: 5/5Assertion failed: false [File:D:\build\++UE5\Sync\Engine\Source\Runtime\Slate\Public\Widgets\Views ...
Orphaned BP actors when using UWorldPartitionBuilder
UE - World Creation - Worldbuilding Tools - World Partition - Nov 21, 2025From an EPS case: --------------------------------- We're seeing a recurring issue where child BP actors are becoming orphaned during any processing that uses UWorldPartitionBuilder. It affects ...
[CrashReport] Mac/Metal Intel compiler crash - UE4Editor-MetalRHI.dylib!CreateMTLRenderPipeline()
UE - Graphics Features - Oct 27, 2017Mark S: This is an Intel compiler failure on macOS 10.12.6. Callstack from LogAssertion failed: [File:/Users/build/Build/++UE4+Release-4.18+Compile/Sync/Engine/Source/Runtime/Apple/MetalRHI/Privat ...
DLC Package content isn't recognized when using RequestAsyncLoad
UE - Foundation - Core - May 24, 2016Attempting to load dlc assets with RequestAsyncLoad function results in the assets not being recognized. ...
Crash due to memory after opening the World Partition window with large objects
UE - World Creation - Worldbuilding Tools - World Partition - Dec 8, 2022Regression: Tested in UE5/Release-5.0, this issue does not occur so regression is yes. Reproducing this issue has a mixed reproduction rate. I have gotten the editor to crash when scaling the cube ...