Crash on adding elements to a TMap property

Tools - Jul 25, 2019

Adding elements to a TMap<int32, int32> causes the editor to crash if the TMap has a default value associated with it. Tested in 4.22 (CL - 4753647), 4.23 (CL - 7445012), 4.24 (CL - 7605614) ...

When using Set Master Pose Component, crash occurs when target has cloth

OLD - Anim - May 18, 2017

Description: Appears directly related to using Set Master Pose Component when the target component has cloth Error message: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Lin ...

Content is Missing from Cook and indeterminism: StaticMeshComponents in Blueprints that copy data into themselves from StaticMesh have indeterminism due to StaticMesh not yet finished loading, postloading, or building

UE - Core - Systems - Nov 12, 2025

Content is Missing from Cook warnings are warnings reported at the end of cook phase of a project's data build. They report that data used by a cooked package will not be available at runtime. This ...

[CrashReport] UE4Editor_SlateCore!FHittestGrid::FindFocusableWidget<<lambda_3a8b364273a2882da220e6e492096c17>,<lambda_d0075a811a928600995d1b2de6795365>,<lambda_105424556dbaeebf7f5bf9bed3e2f737> >() [hittestgrid.cpp:397]

UE - Editor - UI Systems - Jun 18, 2018

No user comments in crash group 394 for (StrideCellPoint[StrideAxis] = StrideAxisMin; StrideCellPoint[StrideAxis] <= StrideAxisMax; ++StrideCellPoint[StrideAxis]) 395 { 396 ** ...

Child actor components fail to attach in cooked builds when mobility is set to movable and end up at the origin

UE - Gameplay - Oct 21, 2025

Context: A Child Actor Component allows an actor in Unreal Engine to contain another actor as its child (component). Problem: The problem is inconsistent handling of child actor component mobility ...

Controller Mapping/Unmapping on some platforms is not ideal for local multiplayer

UE - Gameplay - Input - Nov 19, 2025

[Link Removed] The workaround is as I posted in the UDN, to override the viewport client or to make a custom slate input mapping to change this behavior. But, there is a bug with that unmapping/l ...

Sequencer fails to package during Build command for ASTC

UE - Platform - Mobile - Jan 15, 2017

When attempting to test for ESDSR on Android, the Sequencer project fails to package towards the end of the Build Command. Runtime/OpenGLDrv/Public\OpenGLESDeferred.h(267,5) : warning: 'OPENGL_ES2 ...

[CrashReport] UE4Editor_Core!FWindowsWindow::Initialize() [windowswindow.cpp:199]

Tools - Mar 1, 2017

Error message: Assertion failed: 0 [Link Removed] [Line: 199] Window Creation Failed (1158) Source Context: 184 VirtualHeight = ClientHeight; 185 186 // We call reshape w ...

Unable to edit double variable in property matrix

UE - Editor - Verse Class Editor - Oct 2, 2023

Since UE5.0, cannot edit double variables in property matrix. In UE4.27, it worked correctly and could be edited from the property matrix. This is because double variables are not supported in SProp ...

Data Asset Deserialization crash after upgrading 4.19.2 to 421.1

UE - Foundation - Core - Feb 7, 2019

The User has provided an extensive log of their code base setup, and the process leading up to when the Assert occurs. "Our game mode & player state FSM are setup in a data driven manor using UDa ...