Unreal Engine Issues
Unreal Engine Issues
Level Instance Property Override: Actor::Tags overridden pre-CS but clobbered by RerunConstructionScripts with no post-CS re-apply
UE - Engine Scaling - Streaming - May 4, 2026Summary When using the Level Instance Property Override system, overrides applied to `AActor::Tags` are silently lost for Blueprint actors whose Construction Script assigns or appends to `Tags`. The ...
Crash when changing a Play Node's "Sequence" to a Montage
OLD - Anim - Jan 20, 2016I understand that this is not something you're intended to be able to do (Montages aren't used this way), but we should bar the user from inserting a montage into this variable slot. Crash occurs w ...
Compile error during build stage when packaging for tvOS
UE - Platform - Mobile - Dec 9, 2016Compile error packaging for tvOS: Does not affect iOSUATHelper: Packaging (tvOS): UnrealBuildTool: D:\Build\joseph.wysosky_Main\Engine\Source\Runtime\Core\Private\iOS\IOSAppDelegate.cpp(388,12): ...
[CrashReport] UE4Editor-ApplicationCore.dylib!FMacWindow::ApplySizeAndModeChanges()
UE - Platform - Apple - Oct 27, 2017This is an early trending Mac crash in 4.18. Users have not provided any descriptions of their actions when the crash occurred. Callstack from LogLogAssetRegistry: Asset discovery search completed ...
[CrashReport] UE4Editor-MetalShaderFormat.dylib!FGenerateMetalVisitor::print_constant()
UE - Graphics Features - Sep 22, 2017This is an early trending crash coming out of the 4.18 previews. It occurs on Mac, and all affected project names indicate it is related to AR. Users have not provided any descriptions of their ac ...
[CrashReport] Linux crash - FScopeContext::FScopeContext()
UE - Platform - Linux - Oct 5, 2017This is a somewhat common Linux crash occurring in 4.17.2. (there are a few older records in 4.16.2 and 4.17.1 also, but most occur in 4.17.2) Callstack from Log[2017.10.04-14.49.42:768][ 2]LogFi ...
Null FPhysicsActorHandle dereference in FBodyInstance::InitDynamicProperties_AssumesLocked when CreateShapes_AssumesLocked fails during async body init
UE - Runtime - Simulation - Aug 2, 2026Summary When CreateShapes_AssumesLocked fails during async body creation, the failed FBodyInstance is left in Bodies[] with a released actor handle. InitDynamicProperties_AssumesLocked is then called ...
[Niagara][5.8] Data Channel Read and Write register with an identical type hash when fx.Niagara.DataChannels.Enabled is set from ini, hitting checkf in FNiagaraTypeRegistry::RegisterTypeInternal
UE - Rendering - Architecture - Niagara - Sep 28, 2026Affects: 5.8 (verified on Release-5.8), Windows, EditorSummary Adding fx.Niagara.DataChannels.Enabled=true to an ini file makes the Niagara editor assert when a Data Channel Read is created. The sa ...
[CrashReport] UE4Editor-MetalRHI.dylib!FMetalRenderPipelineDesc::CreatePipelineStateForBoundShaderState()
UE - Graphics Features - Jun 29, 2017This is a common crash affecting Mac users in the 4.16 release. Mark.S: "one of the visualisation shaders is setting up bogus render state" Callstack from LogLogActorFactory: Actor Factory create ...
Navigation crashing on PIE in absence of NavOctree
UE - AI - Mar 17, 2015Access violation - code c0000005 (first/second chance not available) UE4Editor_Engine!UNavMeshRenderingComponent::GatherData() + 18874 bytes [e:\downloads\unrealengine-4.7\unrealengine-4.7\engine\s ...