Unreal Engine Issues
Unreal Engine Issues
Linux Crash Reporter can fail due to exceeding crash malloc space when generating the report
UE - Platform - Linux - Sep 16, 2026On Linux a crashing process can fail to produce a crash report at all. The crash folder is created and contains CrashContext.runtime-xml and Diagnostics.txt, but the copied log file is 0 bytes, Cras ...
Unexpected offset when using attach tracks with scene root components
UE - ACT Character - Sequencer - Sep 15, 2026We noticed an inconsistency when using attach tracks, depending on whether or not the parent actor has a default scene root. This creates an unintuitive behaviour for animators. It can be reproduce ...
World Partition - HLOD: baked HLOD textures contain unresolved runtime virtual texture content
UE - Engine Scaling - Streaming - Sep 15, 2026Baking HLODs for actors that sample Runtime Virtual Textures produces incorrect baked textures: blurry or unresolved RVT tiles, fully black tiles on the first bake of an editor session, and washed-o ...
SceneCaptureComponent2D destroys shared Lumen Radiosity atlases every frame, breaking temporal accumulation in the main view
UE - Rendering - Features - Lumen - Sep 14, 2026A USceneCaptureComponent2D with bCaptureEveryFrame = true and default post process settings causes FLumenSceneData::IndirectLightingAtlas and RadiosityNumFramesAccumulatedAtlas on the sharedScene->D ...
Custom Debug Camera Is Not Respected If Set Anywhere Other Than Code
UE - Gameplay - Gameplay Cameras - Sep 11, 2026The correct debug camera is no longer used if the class is set in a config file or within the Editor. When the debug camera is toggled on, the default will be used instead. If the class is set in co ...
Scrubbing the timeline in Sequencer can hang the editor when operating on constrained actors with complex control rigs
UE - ACT Character - Anim in Engine - Sep 11, 2026The issue is caused by UAnimDetailsProxyManager::ForceUpdateProxyValue triggering evaluation of constraints that are attached to control rigs. When scrubbing, requests to ForceUpdateProxyValue are ...
Race condition in GetFunctionSig_Write() and other function signatures
UE - Rendering - Architecture - Niagara - Sep 11, 2026A race condition exists in GetFunctionSig_Write() and other places where FNiagaraFunctionSignature is lazily initialized because multiple worker threads can progress past if (!Sig.IsValid()) and st ...
Motion blur artifacting in MetaHuman Crowd demo
UE - Rendering - Features - Sep 10, 2026This issue was reported by a licensee and we also hit it during dev work on the crowds demo. It seems that this may be a general issue with motion vectors and teleporting actors as there are variou ...
TMap where key is an FString: initializer list will accept bad MakeTuple
UE - Core - Systems - Sep 2, 2026POST LINK: https://forums.unrealengine.com/t/tmap-where-key-is-an-fstring-initializer-list-will-accept-bad-maketuple/2747443 POST BODY:Summary A TMap where the key is an FString can be created lik ...
Level Sequence spending long time validating assets
UE - ACT Character - Control Rig - Aug 31, 2026Hi After migrating our animation project from 5.7 -> 5.8 we notice that some level seqeunces take much longer to save (during validation stage). This issue only exhibits when using control rigs in ...