Renaming a level by WorldPartitionRenameDuplicateBuilder fails if the level contains GroupActor with non-spatial actors

UE - World Creation - Worldbuilding Tools - World Partition - Oct 24, 2023

Referece to the source level should be fixed by FReplaceObjectRefsArchive, but it is not working because ArIsModifyingWeakAndStrongReferences is not set. It can be fixed by setting the flag.class FR ...

Reimporting a static mesh will cause some values to be reset back to defaults

Tools - Jul 5, 2017

Reimporting a static mesh will cause some Static Mesh Editor values to be reset back to defaults. This was reported as JIRA UE-22205 back in 4.10 and was marked fix in 4.12. However, I wasn't able ...

Renaming native struct with redirect can break user defined structs

UE - Gameplay - Blueprint - Jul 18, 2018

From https://udn.unrealengine.com/questions/444690/redirecting-ustruct-used-as-member-of-userdefineds.html In 4.20 it was changed so soft object ptrs pointing to classes work correclty with +ClassR ...

Huge performance hit when recording a demo (demorec)

UE - Networking - Jun 3, 2019

The current engine version (4.22) seems to suffer a huge performance hit when using the demo recording (demorec) feature. This issue is present in both the editor and the packaged game (developer bu ...

Selecting multiple actors with differing DataTableHandles causes data loss

UE - Gameplay - Jan 4, 2021

The data table customization (and probably others) tries to aggressively clear out row references that are not valid in the table they point to. This breaks when selecting multiple actors or objects ...

Pressed event triggered after calling FlushPressedKeys while holding the button

UE - Gameplay - Input - Oct 2, 2024

This is an issue related to the behavior of the FlushPressedKeys function when called manually while a button is held. Once the function is called in C++, a Pressed event gets triggered even though ...

In -game in Editor, if streaming-in a LevelInstance and initialize its world partition, then leaving that cell and make it go outside the streaming grid, to re-enter it again, will trigger a check(!StreamingPolicy) if no GC has happened during that time.

UE - World Creation - Worldbuilding Tools - World Partition - Jan 27, 2025

This crash can be fixed by adding a couple of || IsRunningGame() like it is done here:    FGenerateStreamingContext Context = FGenerateStreamingContext()        .SetLevelPackagesToGenerate((bIsPIE ...

MediaFramework movies not playing properly in Shipping

Media Framework - Nov 7, 2017

`check(Samples.Pop());` this kind of `Pop()` inside of a `check()` is in a few places in MediaSampleQueue.h and MediaSamples.cpp but `check()` expands to nothing in Shipping/Test, so, required work ...

Assertion Failure: Cascade Particle !bPostTickComponentUpdate in same tick group as Cascade Particle system submission.

UE - Niagara - Apr 18, 2019

Attached Project:  [Link Removed] Since Upgrading project to 4.22, Licensee has been experiencing an Assertion crash in their built game. "I'm not exactly sure why it crashes. It's a very specific ...

Suspension CoM calculations don't update with mass.

UE - Simulation - Physics - Dec 15, 2016

UWheeledVehicleComponent calculates the Suspension settings only when the physics state is first created. When CoM is set through the editor, the vehicle is constructed with the appropriate offset ...