Unreal Engine Issues
Unreal Engine Issues
Map placed actor binding to another actor's Event Dispatcher (multicast delegate) results in duplicate bindings after blueprint recompile
UE - Framework - Blueprint - Apr 17, 2025Context Blueprint actors placed on the map can bind to another actor's event. If an ActorB has a reference to ActorA, it can bind to an event dispatcher in A by creating an event node in ActorB's e ...
Static Mesh cooking: Bad mesh description should not crash the cooker
UE - Graphics Tools - Modeling Tools - Mesh Editing - Aug 21, 2023FStaticMeshRenderData::Cache has the assertion: checkf(Owner->IsMeshDescriptionValid(0), TEXT("Bad MeshDescription on %s"), *GetPathNameSafe(Owner)); This assertion can be triggered by data erro ...
Slate Widget fails to compile once added to a new project
UE - Foundation - Core - Jan 28, 2015Slate Widget fails to compile when you add it to a new project. Expected as a user that anything in that default list should be able to be added and compile fine without making any changes. Compil ...
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 ...
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] Assertion failed on Linux: SharedContext.hGLContext in OpenGLLinux.cpp
UE - Platform - Linux - Jun 16, 2017This is a top community crash occurring on Linux. The two linked CrashGroups have nearly identical callstacks. A log file is attached. Additional information is currently unavailable. Callstack f ...
[CrashReport] Assertion failed: TaskDataArray.Num() == Exporter->VolumetricLightmapTaskGuids.Num()
UE - Graphics Features - Lumen - Oct 2, 2017This is a trending crash coming out of the 4.18 Previews. Users have not provided any descriptions of their actions when the crash occurred, but at least two of the affected projects are being creat ...
[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 ...