Android app will get crashed if it disable HDR and run with Vulkan API

UE - Platform - Mobile - May 17, 2018

The backtrace is: F/DEBUG   : backtrace: F/DEBUG   :     #00 pc 00070e22  /vendor/lib/hw/vulkan.msm8994.so (A4xCommandBuffer::HwProcessWorkload(QglWorkload*)+585) F/DEBUG   :     #01 pc 0004758d  / ...

Sequencer frame range progression is not continuous

zComponent - Archive - Oct 28, 2021

The end of the level visibility section places a DeterminismFence. This causes the issue. The fence clips the frame range and produces a discontinuous frame ranges, e.g. 23201~24000, then 24001~24 ...

Camera behavior during "Orbit Pan Mode" (Alt+MMB+Drag) is wrong while piloting an actor

UE - Editor - Nov 18, 2025

In the Level Editor, dragging the mouse while the "Alt" key is pressed performs one of the "Orbit" movements: OrbitRotation, OrbitPan, OrbitZoom. The same can be done while Piloting an actor. Howev ...

[CrashReport] Linux crash - TOpenGLBuffer<FOpenGLBaseVertexBuffer, 34962u, &()

UE - Platform - Linux - Sep 14, 2017

This is an infrequent Linux crash that has affected a few users in 4.17.1 Callstack from Log[2017.09.12-17.23.41:651][ 0]LogRHI: OpenGL MajorVersion = 4, MinorVersion = 5, ShaderPlatform = GLSL_43 ...

Crash in GC - FSharedStruct reachability race condition

UE - Core - Systems - Jul 13, 2026

This Jira was created from the linked EPS case: =============================================== This issue is caused by FSharedStruct batching reachability requests to the same underlying FInstan ...

iOS/tvOS fails to build from source editor built with Xcode 9.3, macro expansion producing 'defined' has undefined behavior

UE - Platform - Mobile - Apr 2, 2018

Trying to launch on or package for TVOS or iOS from a source build of Mac or Windows will fail with errors:[2018.04.02-16.35.08:522][634]LogPlayLevel: In file included from /Volumes/Storage/GitHub ...

VerboseCookerWarning warnings: Saving object into cooked package %s which was created at cook time, Object Name UniqueObjectNameForCooking_0, Full Path %s, Outer class %s

UE - Core - Data Pipeline - Cooker - Jun 19, 2023

Creating objects at cook time that are exported into the cooked package is a possible cause of indeterminism, and therefore we have banned it in engine classes and will fire a warning about it. Cur ...

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, 2026

Summary 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 ...

[CrashReport] Mac crash - FMetalRenderPass::AsyncCopyFromBufferToTexture()

UE - Graphics Features - Sep 14, 2017

This is an infrequent Mac crash that has occurred for a few users since 4.16. Users have not provided any description of their action when the crash occurred. Callstack from Log[2017.08.26-18.54.51 ...

[CrashReport] Assertion failed on Linux: SharedContext.hGLContext in OpenGLLinux.cpp

UE - Platform - Linux - Jun 16, 2017

This 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 ...