Crash in NaniteStreamManager when Nanite data fails to decode corrupt data from DDC

UE - Graphics Features - Nanite - Sep 11, 2024

If Nanite data becomes corrupt in the DDC, the Editor may crash in FStreamingManager::InstallReadyPages() when the Pending.State is FPendingPage::EState::DDC_Ready but the resulting SrcPtr is null b ...

Default subobject of dynamic component skips initial replication

UE - Networking - Sep 11, 2024

Because the component's subobjects are replicated before the component, the content block for the subobject is received before the component has been created on the client. Since this subobject is c ...

Swapping the Child Actor Class of a ChildActorComponent back to a previously selected BP leads to an Editor crash from illegal Renaming

UE - Gameplay - Components - Sep 11, 2024

A fatal error occurs if we change a Child Actor Class from one BP (ex. "BP_A") to a different BP ( ex. "BP_B") and later change it back to the first BP (ex. "BP_A") without compiling the BP between ...

VisionOS deferred renderer regression

UE - Platform - XR - Sep 11, 2024

Deferred desktop renderer does not function correctly on visionOS.  It did work in 5.4.  One problem is the r.XRMSAAMode setting forcing 4 samples even when not using msaa, but there are other probl ...

During SIE (simulate) and ejected-PIE, modifying a map actor causes triggers RerunConstructionScript() which discards all runtime modifications to SCS components

UE - Gameplay - Blueprint Runtime - Sep 6, 2024

When Simulating, or Playing-In-Editor and ejected, modifying an actor in the editor world causes the SIE/PIE runtime actor to recreate its blueprint added components via AActor::RerunConstructionScr ...

Incremental GC vs Loading Screens deadlock

UE - CoreTech - Sep 5, 2024

A licensee is reporting that using a loading screen with the incremental garbage collector can result in a dead lock when a loading screen is displayed. The licensee found out that:  -------------- ...

Server only network emulation settings applied to client on travel

UE - Networking - Sep 4, 2024

It looks like the "Server Only" emulation settings are being applied to the client after a travel. When doing a server travel with the TRAVEL_Relative travel type, the NextURL created in AGameModeBa ...

FDateRange cannot be declared as UPROPERTY

UE - CoreTech - UObject - Sep 4, 2024

Unlike other range wrapper structs, such as FFloatRange, marking a FDateRange as a UPROPERTY results in the following error: error : Unable to find 'class', 'delegate', 'enum', or 'struct' with nam ...

EditorOnlyReferences on actor descriptions are not properly computed/can include non editor only references

UE - World Creation - Worldbuilding Tools - World Partition - Sep 3, 2024

From licensee:"[...] the issue is that ActorsReferencesUtils::GetActorReferences (/FArchiveGatherExternalActorRefs) will only analyze a reference to an object (/actor) once, if it's editor only the ...