Unreal Engine Issues
Unreal Engine Issues
Duplicating / Moving (to another level) an actor with a Hierarchical Instanced Static Mesh component causes a crash
UE - Graphics Features - Nov 14, 2016When you have an actor with a Hierarchical Instanced Static Mesh component that has a Static Mesh set and is populated with at least 1 instance and then duplicate it or move it to another level, it ...
Building for Gear VR Distribution fails due to missing Oculus lib
UE - Platform - XR - Jun 7, 2017Users have reported that building for Distribution on Gear VR results in failure due to a missing Oculus library. The error they receive is as follows: UATHelper: Packaging (Android (ETC2)): [javac ...
ISM + WPO = broken motion vectors?
UE - Rendering - Features - Nov 5, 2024Instanced Static Meshes will have incorrect velocity if a Material uses World Position Offset. Fixed WPO in a material causes significant velocity on the ISM. This was also replicated in //UE5/Rele ...
Displaying Revision control history for a file ending in an "undo" of a revision can cause a crash
UE - Editor - Jun 18, 2024This crash is caused by how source control history is managed and shown. In this specific case the source control software is Perforce. As written in the repro steps, it can happen to any uasset tha ...
Ensure triggered in FBoundsCacheElement::GetValue when adding ISM instances in Construction Script
UE - AI - Oct 8, 2025An ensure is triggered in FBoundsCacheElement::GetValue when adding instances to an InstancedStaticMeshComponent inside a Blueprint’s Construction Script. This occurs when the ISM component is navig ...
Update prepackaged dotnet to latest 10 patch release due to crash on Mac OS.
UE - Platform - Mac - Sep 24, 2026A dotnet crash occurs sporadically with a sigsev or sigbus when running on Mac OS. This is in the dotnet executable itself, and can happen on commands like `dotnet build`, not just on executing the ...
Sampling Scene Texture in Custom Expression in Post Process Material Breaks Viewport UV
UE - Graphics Features - Apr 6, 2018This issue does not occur in 4.18.3 but does occur in 4.19 and Main, making this a regression. Per user: I suspect there's an issue with custom expressions and sampling coordinates. It appears onc ...
[CrashReport] UE4Editor_BlueprintGraph!BlueprintActionFilterImpl::IsEventUnimplementable() [blueprintactionfilter.cpp:588]
UE - Gameplay - Blueprint - Jun 1, 2016This crash has been reported through the 4.12 Previews and is continuing to occur in the 4.12.0 release. Additional information about this crash is not available at this time, however it may be the ...
The FNetNameMapping::GetUniqueName function appends numerical values to the end of the previous name instead of replacing the previous name's numerical value
UE - Gameplay - Blueprint Compiler - Feb 23, 2018The GetUniqueName() function attempts to make sure that all node names are unique. For nodes that are used a large number of times, it adds a numerical value to the end of the name. Prior to 4.18, t ...
ModularGameplay and other runtime plugins have wrong LoadingPhase
UE - Gameplay - Jun 30, 2022Plugins that provide blueprint-accessible libraries generally need to be set the PreDefault LoadingPhase so they can be properly loaded before game-specific data that loads early in the Default load ...