Paper2D: Editor hangs when assigning Sprite Atlas Group to Sprite

UE - Gameplay - Paper2D - Dec 16, 2025

In UE 5.3 and later, assigning a Sprite Atlas Group to a UPaperSprite asset can cause the editor to hang and eventually crash. This behavior has been reproduced in 5.3, 5.6, and a recent UE5-main so ...

Frame-locked sequencer intermittently triggers notify state end event

UE - Anim - Runtime - Mar 10, 2026

Frame-locked Sequencers can occasionally produce frames with a zero delta time due to frame number truncation. When this occurs, if the animation cursor is within the range of a Notify State that is ...

RemoteMac.cs fails to build if ProjectFile is null

UE - Platform - Mobile - May 17, 2019

See CL 6473818. Remote compiling on a Mac is triggering a NullReferenceException for me, making me unable to build. I was able to delete the crashing lines locally to work around it for now.line 91 ...

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 ...

Unable to add/compile code for Automation Test

UE - Automation Test - May 22, 2017

When following the documentation on setting up automation tests, the sample provided for "Simple Tests" does not successfully compile. One of two compiles errors is given based on the TFlag used A ...

World Partition Converter- Soft object pointers to actors kept in scripted sublevels are incorrectly remapped to the main world during in place conversion

UE - World Creation - Worldbuilding Tools - World Partition - Jul 1, 2022

From user:"We have ran into an issue with soft object pointer fixup/remapping with the World Partition converter. If you have a sublevel that contains a level script and an actor that is hard refer ...

Crash when save the blueprint function variable that set the StringTable asset

UE - Foundation - Core - Apr 17, 2019

This issue doesn't crash in 4.21. It is rewritten as GIsSavingPackage = true in UPackage::(Save() when Blueprint is saved, but it's rewritten as false in 4.21. Workaround Do not set the String Tab ...

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

UE - Simulation - Gameplay - 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 ...

Crash applying animation blueprint with sub instance to Skeletal Mesh Component

OLD - Anim - Aug 3, 2016

Crash occurs when the user sets Anim Class in a Skeletal Mesh Component to an animation blueprint with a Sub Anim Instance node. ...

Compile fails when attempting to launch on to Windows with Raw Input plugin enabled

UE - Gameplay - Input - Nov 9, 2016

Compile fails when the user attempts to launch on to Windows with the Raw Input plugin enabled. Error:LogPlayLevel: xgConsole: Module.RawInput.cpp LogPlayLevel: xgConsole: d:\framework\engine\plug ...