Unreal Engine Issues
Unreal Engine Issues
[CrashReport] Assertion failed: Array index out of bounds - GetPhysicsTriMeshData() [modelcomponent.cpp:688]
UE - Simulation - Physics - Oct 30, 2017This is a semi-common crash that has occurred since at least 4.17.1. The callstack is nearly identical to [Link Removed], which was fixed in 4.18.0, however the error message and source context are ...
Assertion failed: (Index >= 0) & (Index < ArrayNum) when importing large Alembic file
UE - Editor - Content Pipeline - Datasmith - Importer - May 3, 2022Regression testing done on //UE4/Release-4.27.2 CL-18427296 and this issue did occur. [Link Removed] [Link Removed] Below is snips of customers description and proposed workaround:Importing alembi ...
Children of editor-only actors do not maintain correct transforms when placed inside level instances for PIE and cooked builds
UE - World Creation - Worldbuilding Tools - Level Instances - Oct 20, 2025We have found an issue where children of editor-only actors get wrong transforms in PIE and cooked builds when placed inside level instances. This affects both engine version 5.5 and 5.6. The issue ...
[CrashReport] Crash on Mac related to cooking for IOS
UE - Graphics Features - Jul 20, 2017This is a common commandlet crash for Mac users in 4.16. In all cases, the command line is like: "(path/project).uproject" -run=Cook -NoLogTimes -TargetPlatform=IOS -fileopenlog -unversioned -ski ...
SteamVR turns off vsync globally
UE - Platform - XR - Feb 21, 2020Additional Info From User: Result: Vsync will get turned off by FSteamVRHMD::Startup() setting a global console variable, regardless of your project configuration. Expected: Vsync is only deacti ...
Crash when trimming animation and then undoing action
UE - Runtime - Animation - May 30, 2023Repro rate: 3/3 times This is a regression as the issue does not occur in 5.1.1 ...
Crash: Direct3DDevice->CreateBuffer failed at D3D11VertexBuffer.cpp with error E_INVALIDARG
UE - Graphics Features - Jul 6, 2017This is a common crash affecting users since at least the 4.14 release. It was previously associated with [Link Removed], however that has been marked as fixed. Source Context 221 void Veri ...
Nanite Displacement Bounds Mismatch Causes Floating Terrain Artifacts on Landscape
UE - Rendering - Graphics Features - Nanite - Mar 19, 2026Summary When Nanite Tessellation (Nanite Displacement) is enabled on a Landscape in UE 5.7.3, scaling the Displacement value via Multiply nodes in the material graph causes floating terrain ghost a ...
FGameplayTagCountContainer::Reset() leaves explicit tag state and causes counts to accumulate
UE - Gameplay - Gameplay Tags - Aug 4, 2026[Summary] In UE 5.7 and later, if a tag is added once to an FGameplayTagCountContainer, the container is reset, and the same tag is added once more, GetExplicitTagCount() returns 2 instead of the e ...
[CrashReport] Assertion on in UMaterialInterface::InitDefaultMaterials()
UE - Graphics Features - Jun 28, 2017This is a common Mac crash occurring in the 4.16.1 release. I have not found any evidence of it occurring on Windows. The callstack closely matches [Link Removed], which was briefly experienced by ...