Unreal Engine Issues
Unreal Engine Issues
Vector VM - Crash / memory stomp when using > 255 external function calls
UE - Niagara - Aug 12, 2025The Vector VM has only every supported a byte's worth of external function calls, when we blew the limit it would index into the incorrect VM call. The new VM will also overwrite memory when exceed ...
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 ...
[CrashReport] UE4Editor_Engine!FDefaultMaterialInstance::GetMaterial() [material.cpp:243]
UE - Graphics Features - Aug 14, 2017This is a trending crash coming out of the 4.17 release that also occurred with some frequency during 4.16. User DescriptionsTrying to apply a material (Normal, Metallic&Roughness, and Basic)I was ...
Grandchild actor with IsEditorOnly enabled is duplicated during save the level.
UE - Gameplay - Components - Dec 6, 2019IsEditorOnly is not reflected in grandchild actor when parent/child/grandchild are constructed with ChildActorComponent. This causes the issue that actor will increase incorrect when save the level. ...
A hidden dedicated server is launched when playing as client
UE - Networking - Jul 15, 2020When we play in editor with the Play Net Mode set to Play as Client, a hidden dedicated server is launched. Previously in 4.24 the dedicated server would always launch with a visible command window. ...
Tracks that manipulate byte properties may have different (non-deterministic) results even for the same frame
UE - Anim - Sequencer - Aug 13, 2024This issue is relatively easy to reproduce, e.g., in the timing of switching between the two types of property operations within the same track. It seems to be easy to reproduce the above problem in ...
Exporting Alembic Skeletal mesh from UE4 to FBX causes a crash
Exporting an alembic skeletal mesh that has been imported and then exporting it to FBX using the asset actions options will cause a crash. Tested with: Crash - 4.13.0 Binary CL-3106830 Crash - 4.1 ...
Lighting still unbuilt in Content Examples Lighting map after building lighting and saving
UE - Graphics Features - Aug 28, 2016Lighting needs to be rebuilt in Content Examples Lighting level every time the editor is reopened. If the user builds lighting, saves the level, closes the editor, then reopens the level, lighting ...
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 ...
[CrashReport] UE4Editor_DetailCustomizations!`FBrushDetails::CustomizeDetails'::`2'::Local::OnClassPicked() [brushdetails.cpp:172]
Tools - Aug 29, 2017This is a common crash that has occurred since at least 4.15 and affected more than 100 users. The callstack shares some similarities to [Link Removed], which was not resolved. User DescriptionsGo ...