"Assertion failed: NumberOfFreeBits >= 0" on clients that attempt to connect to a server with the -NoPacketHandler option

UE - Networking - Oct 6, 2020

With the rework of IP address resolution in 4.25, this assert now occurs. When no packet handler is used, UPendingNetGame::InitNetDriver calls SendInitialJoin() immediately, before async address res ...

Crash when deleting the Add Component By Class node after changing the Relative Transform of the component

UE - Gameplay - Blueprint - Mar 31, 2021

When adding the Add Component By Class node, choosing a class that has a Relative Transform pin, changing the transform, and deleting the node the editor crashes. I tested this with the Skeletal Mes ...

Color space transform in the UI composition is incorrect on DX12 HDR (r.HDR.UI.CompositeMode=1)

UE - Graphics Features - Jun 11, 2021

Color space conversion in the UI composition is incorrect on DX12 HDR. In the main() function In CompositeUIPixelShader.usf, you can see the following color space transform.// sRGB -> RRT -> ODT ...

Material slot assignment incorrect after mesh reduction completely removes all triangles from a section

When mesh reduction results in a section becoming empty, the material slots are incorrectly assigned. e.g. if section 0 gets removed due to it having no triangles after reduction, then its material ...

Deferring Blueprint CDO construction at load time is leading to some data loss.

UE - Gameplay - Blueprint - Jan 27, 2023

Various licensees are reporting data loss on load due to the change that was made for [Link Removed] in which we now defer Blueprint CDO construction on load until the finalization phase. This issu ...

UKismetArrayLibrary::GenericArray_Shuffle is weighted to return some results more than others

UE - Gameplay - Aug 15, 2017

The implementation of UKismetArrayLibrary::GenericArray_Shuffle() will generate certain array shuffle results more often (up to three times as much) than others, rather than having a roughly equal c ...

[CrashReport] ULevel::GetWorldSettings() - UMaterialInstanceThumbnailRenderer::Draw

Tools - Aug 29, 2017

This is a common assertion that has occurred since at least 4.14 and affected nearly 100 users. The callstack is similar to [Link Removed], which was marked fixed for 4.14. User DescriptionsUndoi ...

Skeletal Meshes have physics collisions lag

UE - Simulation - Physics - Oct 2, 2019

Skeletal mesh's physics collision lag behind the actual mesh. It didn't matter if there was just a root bone or multiple bones/constraints. This doesn't happen when using static meshes. The effect ...

Calling Array_Identical in a blueprint results in a compile failure with nativization

UE - Gameplay - Blueprint - May 13, 2020

REGRESSION Does not occur in 4.24 Blueprints that call Array_Identical results in a failure during nativization:F:/Projects/Release/TestNativizeArray/Intermediate/Plugins/NativizedAssets/Windows/Ga ...

Changing the name of a native component results in a blank details panel

UE - Gameplay - Components - May 7, 2021

Much like [Link Removed] (which I'm backing down on my by design claim), there is an issue where if you previously referenced a component that no longer exists, the correct instanced subobject is lo ...