Unreal Engine Issues
Unreal Engine Issues
UClass::SparseClassDataStruct null at editor-time for child blueprints until compile
UE - Framework - Blueprint - May 29, 2024Child blueprints of a blueprint of a native actor class with sparse data can have an incorrectly null SparseClassDataStruct value, and thus fail to initialzie their SparseClassData. This affects edi ...
[CrashReport] UE4Editor_Renderer!TStaticMeshDrawList<TBasePassDrawingPolicy<FUniformLightMapPolicy> >::GetUsedPrimitivesBasedOnMaterials() [staticmeshdrawlist.inl:868]
UE - Graphics Features - Feb 19, 2016This Jira was entered due to a high number of occurrences in 4.11 Preview 5. Error message: Assertion failed: !Proxy->IsDeleted() [Link Removed] [Line: 867] Source Context: 853 { 854 ...
[CrashReport] Access Violation - UModelComponent::GetPhysicsTriMeshData() [modelcomponent.cpp:673]
UE - Simulation - Physics - Oct 2, 2017This is a trending crash coming out of the 4.18 Previews. Users have not provided any descriptions of their actions when the crash occurred. The callstack is similar to [Link Removed], which was ju ...
Non-reflected header files not recognized by UHT
UE - Foundation - Core - Jul 28, 2015A user adds 3 .h files though Visual studio where the first contains a struct, the 2nd includes the 1st, the 3rd includes the 2nd and tries to make a variable of the struct declared in the 1st. The ...
[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 ...
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 ...
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 ...
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 ...