ISM + WPO = broken motion vectors?

UE - Graphics Features - Nov 5, 2024

Instanced 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 ...

Duplicating Example Level Prevents the Copy From Being Saved

Tools - Oct 27, 2015

In a project, if you duplicate the example level and attempt to save it, the save will finish, but the asterisk will remain on the file. Attempting to open the duplicated map will prompt another sav ...

PhysX Crash when spawning Instanced Static Mesh actors at Runtime

UE - Simulation - Physics - Destruction - Oct 13, 2015

Bug generated from crash reporter. This crash has been found in 4.7.6 and still occurs in 4.8.3 and 4.9.2 to users. One user in particular still, and he experiences it often. I have not been able ...

Custom Widget does not change cursor settings

UE - Editor - UI Systems - Nov 20, 2017

When you are using a Custom Widget, changing the cursor setting does not change cursor during PIE or packaged games. only changing the cursor options in the original widget fixes the issue. This iss ...

Imported heightmaps with 2x2 sections crash editor

UE - LD & Modeling - Terrain - Landscape - Jul 18, 2016

Importing a heightmap with 2x2 segments seems to cause the editor to crash in 3 different instances: 1. Importing the same 2x2 segment landscape a second time after deleting the first instance 2. ...

Previewing Node in Material Editor Produces Unexpected Output with DX12

UE - Graphics Features - May 16, 2018

Per Licensee: Since we switched to DX12 we started to see strange behavior in material previews. I was able to reproduce the problem in UE 4.19 vanilla as well. We usually have to force recompilin ...

Undo function breaks local variables in Blueprint Function after compiling

UE - Gameplay - Oct 8, 2020

Blueprint functions appear to correctly associate local variables when renaming the function. However when undoing a rename with ctrl-z the local variables appear to lose their association. Redoing ...

FCableSceneProxy::BuildCableMesh thrashes memory allocator

UE - Simulation - Physics - Feb 12, 2025

FCableSceneProxy::BuildCableMesh in CableComponent.cpp:233 showed up as a hot spot in profiling because the two TArray allocators in SetDynamicData_RenderThread used by BuildCableMesh are created an ...

Crash when saving a Data Table that is referencing itself in a Data Table Row Handle

Tools - Feb 23, 2017

Crash when saving a Data Table that is referencing itself in a Data Table Row Handle. Reopening the project also causes a crash. *Regression: Yes This was fixed and working in 4.13-3037605 This i ...

Landscape Grasstype warning causes log spam when landscape is streamed in or out

UE - LD & Modeling - Terrain - Landscape - Nov 16, 2016

Using the Landscape Grasstype will generate log spam for the number of Landscape components being used or if using World Composition will generate a log warning for each tile used. The warning ind ...