Unreal Engine Issues

NPC - Does not get updates from Material Parameter Collection changes in the editor

When an MPC is selected as the Source Material Collection for an NPC, all of its current parameters are carried over to the NPC with their current values. After that, if parameters are added to, rem ...

FBoneContainer::MakeMeshPoseIndex crash (out-of-bounds array)

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

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 ...

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

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 ...

Nanite can assert in ValidateFixupChunk: 'Assertion failed: HierarchyNodeIndex < Resources.NumHierarchyNodes'

Reported by a licensee. More discussion in the linked UDN case. "Sometimes the WorldPartitionBuilderCommandlet will fail after encountering this error:" Error: Assertion failed: HierarchyNodeIndex ...

[StateTree] Linked Asset trees do not properly transition when On Tick transition is triggered on linked asset that transitions to Tree Succeeded

Linked Asset trees do not transition correctly to Tree Succeeded if using an On Tick transition. The Debugger shows that the transition is triggered repeatedly but no state change occurs. Instead, t ...

Unable to Use Console Command with bShowLaunchImage=False

Disabling Disregard for GC with an invalid asset in GameplayTagTableList causes a controlled crash

Disabling Disregard for GC leads to a crash in GarbageCollectionVerification.cpp VerifyObjectFlags. This crash occurs when there is an invalid path specified in GameplayTagTableList. The cause of t ...

Chaos Cache : When Min Speed To Spawn Trailing Particles > 0, particles are never spawned by chaos cache trailing events

Because UniagaradataInterfaceChaosDestruction::HandleTrailingEvents does not respect incoming TrailingEvent data, the debris velocity during chaos cache playback is always evaluated as zero. The fo ...

Interchange Dialog view resets when changing values

This happens with just about any option in any tab. QA confirmed it also happens in the Material tab. Regression: Yes - does not occur in //UE5/Release-5.4 @ CL34507850 - Binary Repro Rate: 10/10 ...