Unreal Engine Issues
Unreal Engine Issues
[CrashReport] Mac crash - UE4Editor-Slate.dylib!PrepassWindowAndChildren(TSharedRef<SWindow, (ESPMode)0>)
UE - Platform - Apple - Oct 27, 2017This Mac crash originally occurred in 4.15 around March 2017, then decreased in frequency during 4.16 and 4.17. It may be starting to trend again in 4.18. There is one record of this occurring in 4 ...
Blueprint macro in a level blueprint causes memory leak
UE - Gameplay - Blueprint - Oct 15, 2019The level blueprint has a macro that references a level. FBlueprintNodeTemplateCache keeps holding this cashe at transition level. Unable to find source-code formatter for language: text. Available ...
Project does not cook with actors containing ModularSynth component
UE - Audio - Sep 11, 2017A project does not cook with actors containing ModularSynth component. The error is a follows UATHelper: Packaging (Windows (64-bit)): Cook: LogWindows: Error: begin: stack for UAT UATHelper: Pack ...
CLONE - Project does not cook with actors containing ModularSynth component
UE - Audio - Sep 13, 2017A project does not cook with actors containing ModularSynth component. The error is a follows UATHelper: Packaging (Windows (64-bit)): Cook: LogWindows: Error: begin: stack for UAT UATHelper: Pack ...
Enum Compare Condition causes crash when resetting default value of right field in State Tree's Enter Conditions
UE - AI - StateTree - Feb 11, 2026In FStateTreeCompareEnumCondition::GetDescription, the Left.Enum value is mistakingly used when setting the RightValue. This causes crashes when resetting the default value of the Right field in an ...
Attached Project Crashing on Play When Using World Origin Rebasing with World Composition
UE - Simulation - Physics - Apr 18, 2017The editor is crashing in the attached project on PIE when World Origin Rebasing is enabled. According to the user, this did not occur in 4.13, but I was unable to test any further back than 4.15, a ...
crash at checkUERenderCommandPipeIsReplaying in RenderScenecpp
UE - Rendering - Architecture - Jul 15, 2024Drawing a material to a render target when that material samples an RVT can cause an editor crash. In our testing, the check() did not always occur on the first PIE session, but would always occur ...
Crashes when attempting to use an Instanced Struct inside Control Rig / Rig VM
UE - Anim - Rigging - Control Rig - Mar 17, 2025Currently, the Control Rig Editor allows the user to use the "Instanced Struct" type, for example for a variable or function input/output. However, this type does not seem to be properly supported ( ...
Editor ensure in USceneComponent::OnComponentDestroyed during Blueprint compilation GC
UE - Framework - Components - Jan 15, 2026An editor-only ensure can trigger during BP compilation when garbage collection cleans up transient components created as part of component replacement. During recompilation, old component instances ...
Destructing NiagaraParameterStores causes multi threading write conflict
UE - Niagara - Jan 26, 2022FNiagaraParameterStore::UnbindAll() may be called from both GameThread and RenderingThread. Each may modify the same Binding array, it causes infrequent crashes. In my environment, I was able to r ...