Race condition in full builds of UE4 engine source

UE - Foundation - Cpp Tools - UnrealBuildTool - Sep 26, 2019

This is a race condition caused by how "Clean.bat", a batch file used during rebuilds, tries to manually rebuild the UnrealBuildTool project when it runs. This causes a spam of UnrealBuildTool build ...

Import Source disappears in Textures after loading asynchronously loaded level

UE - Editor - Content Pipeline - Import and Export - Dec 15, 2015

It looks like when reimporting a texture asset into the engine after loading a level, you will be confronted with the File Selection box and not the reimport successful notification. In fact if you ...

Crash Re-Importing animation with Additive Layer Tracks after adding a bone to the hierarchy

OLD - Anim - Feb 13, 2017

Error message: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 633] Array index out of bounds: 68 from an array of size 68 Source Context: 733 734 Extrac ...

[CrashReport] UE4Editor_CoreUObject!UObjectPropertyBase::Identical() [propertybaseobject.cpp:60]

UE - Foundation - Cpp Tools - Hot Reload - Nov 17, 2016

This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Error message: Access violation - code c0000005 (first/second chance not available) Source C ...

Unfocused Standalone window has reduced performance

UE - Rendering - Architecture - RHI - Aug 25, 2020

User description: When I run two windowed standalone instances to test multiplayer, the unfocused window gets about 2-5 fps...but if I focus on it, smooth 120fps, yet the opposite screen is now onl ...

NVIDIA 5080 GPU Crash when launching City Sample with DX12

UE - Graphics Features - Lumen - Apr 16, 2025

UPDATE This issue no longer reproduces on driver versions 580.88 and higher. City Sample game crashes immediately upon opening with a NVIDIA 5080 with the latest drivers as well as some previous dr ...

[CrashReport] UE4Editor_PropertyEditor!FDetailCategoryImpl::GetParentLayoutImpl() [detailcategorybuilderimpl.h:168]

Tools - Aug 22, 2016

This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Descriptions from users are provided below. Error message: Assertion failed: IsValid() [Link ...

Crash handling: Prevent reports of assertions during shutdown after an assertion

UE - CoreTech - Aug 8, 2024

CriticalErrors in FWindowsErrorOutputDevice::Serialize (and other platforms) run some code after the error is detected rather than immediately terminating the process. Some of this other code is spe ...

[CrashReport] Crash in TerminateOnDeviceRemoved() - DXGI_ERROR_DEVICE_HUNG

UE - Graphics Features - Aug 29, 2016

Error message: Fatal error: [Link Removed] [Line: 176] Unreal Engine is exiting due to D3D device being lost. (Error: 0x887A0006 - 'HUNG') Source Context: 161 162 const TCHAR* Reas ...

LoadErrors:Warning: Warning CreateExport: Failed to load Outer for resource when moving Blueprints folder to another folder

UE - Gameplay - Blueprint - Apr 14, 2017

There are 3 assets from Content > Blueprints > Missing Types that are failing to be moved over The assets are causing the warnings are:BP_NodeClassIsMissingBP_ParentClassIsMissingTypeBP_PinReferenc ...