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 ...
Crash on Linux and Windows with Vulkan when adding Atmospheric Fog to a Level
UE - Graphics Features - Dec 5, 2018Adding an instance of Atmospheric Fog to a Level causes the Editor to crash on both Linux and Windows when using Vulkan. There is a different callstack when SteamVR is enabled on Linux which is also ...
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 ...
Crash when trimming animation and then undoing action
UE - Anim - Runtime - May 30, 2023Repro rate: 3/3 times This is a regression as the issue does not occur in 5.1.1 ...
Exception on missing file during GC in horde storage
UE - Foundation - Horde - Storage - May 7, 2025During GC, if a file was manually deleted (but the storage system is still track), GC can erroneously fail (and never remove the reference). This causes a backup in GC, putting the whole algorithm i ...
FBX: Camera imports to Matinee with skewed position and rotation
UE - Editor - Content Pipeline - Import and Export - Aug 27, 2013Branch Build Label Changelist UE4-Main UE4_[2013-08-27_14.24] 1799942 DESCRIPTION: When importing an animated camera from Maya into Matinee, the placement of the camera is changed (shifted 90 ...
Ensure/Crash upon opening TM-Hair with Vulkan RHI | Ensure condition failed: DepthStencilLayout == VK_IMAGE_LAYOUT_DEPTH_STENCIL_READ_ONLY_OPTIMAL
UE - Rendering Architecture - RHI - Oct 7, 2020Ensure happening on both Linux and Windows when using Vulkan RHI. Editor will Crash on Linux however when map TM-Hair is opened. Not a Regression, TM-Hair and Grooming feature is new to 4.26 and do ...
NPC - Instances does not get updates from changes to the parent Niagara Parameter Collection in the editor
UE - Niagara - Oct 4, 2024When an Niagara Parameter Collection (NPC) is selected as the parent Collection for an NPC Instance (NPCI), all of its current parameters are carried over to the NPCI with their current values as th ...
Niagara - When Interpolated Spawning is disabled, the first frame of each particle unexpectedly does not take into account the Particle Update stage
UE - Niagara - Feb 28, 2025Foreword: Even if the behavior described here is by design, it is rarely (if ever) expected or desired. This was discussed and agreed to be treated as a bug. Explanation below. When interpolated sp ...