Crash when enabling dynamic branch on static switches in Post Process Materials

UE - Rendering Architecture - Materials - Jun 28, 2023

[Link Removed] Some functions to access parameters don't take into account the newly added runtime static switch parameters. It should be straightforward to fix these up: void UMaterialInstance:: ...

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, 2025

Foreword: 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 ...

Material expression If node has been broken, major regression that shipped in 4.6

UE - Graphics Features - Dec 9, 2014

This sounds legit. Anyone mess with the if node recently? There seems to be a regression where existing content is broken. This should be fixed ASAP and patched into 4.6. https://forums.unrealen ...

Attempting to Open a Widget Blueprint With Animation and Timeline Panels Hidden Causes the Editor to Crash

UE - Editor - UI Systems - Nov 11, 2015

When you attempt to open a widget blueprint when you have hidden the animation and timeline panels, the editor will crash. There is a workaround: Window->Reset Layout will allow you to open the blu ...

MaterialTextureScale calculated incorrectly for materials with WorldPositionOffset

UE - Rendering Architecture - Materials - Apr 16, 2024

When a Material uses WorldPositionOffset, the MaterialTextureScale is calculated incorrectly because FMaterialUtilities::ExportMaterialUVDensities() calls FMeshRenderer::RenderMaterialTexCoordScales ...

Using a FormatText node with Specifier in the same graph as an empty Macro will freeze the editor

UE - Gameplay - Blueprint - Jun 17, 2016

Using a FormatText node with Specifier in the same graph as an empty Macro will freeze the editor. Not using the Specifier or deleting the unused Marco will allow the BP to compile fine. **Only rep ...

After Seamless Server Travel, the Client cannot move the character or see the Server character

UE - Networking - Jul 9, 2015

After Seamless Server Travel, the Client cannot move the character or see the Server character. On the Server, the Client character appears to be falling in place. Tested in both first and third per ...

Multiple Materials not assigned to Mesh on Import

UE - Editor - Content Pipeline - Import and Export - Jan 6, 2017

Not all material elements are created and assigned to the static mesh using multiple materials. With the attached mesh, only the first element is created and the other two are left non-existent. I c ...

Each adding a static mesh not containing any collision data keeps increasing PhysX memory

UE - Simulation - Physics - Apr 19, 2021

If the static mesh has UseSimpleCollisionAsComplex and does not have any SimpleCollision shapes, The physics actor will be destroyed immediately in FInitBodiesHelperBase::CreateShapesAndActors, but ...

TextRenderComponents not parallel safe. Can cause crash

UE - Graphics Features - Feb 28, 2017

Licensee has reported intermittent crashes when loading a map that contains Child Actors with Text Render Components. When the child actor blueprint is spawned all of the text render components st ...