Unreal Engine Issues
Unreal Engine Issues
Sequencer: Entity task Pre/Post callbacks are skipped despite ForcePrePostTask when a required component is absent
UE - ACT Character - Sequencer - Oct 13, 2026Tasks scheduled through the entity task builder with FTaskParams::ForcePrePostTask() are documented to run their PreTask and PostTask callbacks even when there is no work for the task body. This gua ...
[Landscape] weightmap layer allocations leak into left/top/top-left neighbor components
UE - Graphics Tools - Terrain - Landscape - Oct 13, 2026In 5.8, weightmap layer allocations of a landscape component leak into its left, top and top-left neighbor components when Edit Layers are merged. Neighbors end up with layers that were never painte ...
Deadlock in URigHierarchy
UE - ACT Character - Control Rig - Oct 12, 2026We are regularly hitting a deadlock on 5.8.3. We have one background worker evaluating an animation, holding the RigHierarchy's ElementsLock and waiting for the global GC lock And one Background w ...
Iris - Crash when reading token data for unregistered token data store
UE - Framework - Networking - Oct 12, 2026FNetTokenStore::UnRegisterDataStore will set the TUniquePtr<FNetTokenDataStore> to null, but it doesn’t resize the TokenDataStores array. If FNetTokenStore::ReadTokenData is later called, it will ge ...
Sequencer custom task scheduler hangs with more than 512 tasks (TDynamicSparseBitSet::IsBitSet and operator|=)
UE - ACT Character - Sequencer - Oct 12, 2026With Sequencer.CustomTaskScheduling enabled, a task graph with more than 512 tasks can hang FEntitySystemScheduler::ExecuteTasks. Reported by a licensee, they hit it with a 528 task graph under Clan ...
UBA: crash related to BeyongTrust PGHook.dll and Detour for local jobs.
UE - Core - Cpp Tools - UnrealBuildAccelerator - Oct 9, 2026A license provided a log containing a UBA crash related to PGHook injecting itself when ISPC runs. ...
Mass instanced skinned mesh sweep removes instances without freeing their ASTP tracks
UE - MVF Character - Animation - Oct 7, 2026When an entity stops being batched into an instanced skinned mesh component, the "Collect unwanted items & remove" sweep removes its instance, but never frees its ASTP track. Only ProcessRemovesForC ...
FMetadata: References to invalid\destructed objects can accumulate in the ObjectMetaDataMap array
UE - Core - Systems - Oct 7, 2026Customers are reporting that the package metadata can end up referencing to non-existing assets or other assets. This causing validation errors in the editor and also generates warnings during the ...
Mutable Material Switch node not working
UE - Runtime - Mutable - Oct 7, 2026When using the Material Switch node in Mutable (UE5.8), I do not seem to get pins to wire in my Materials to switch between. Other switch nodes like Mesh Switch seem to work fine. ...
Substrate: FPrimitiveViewRelevance::operator|= bitwise-ORs SubstrateUintPerPixel, inflating the per-pixel byte count and asserting under the blendable GBuffer
UE - Rendering - Features - Shading Models - Oct 6, 2026A crash can occur due to this check in Substrate.cpp when a material with 2 units and a material with 5 (20 bpp) uints are combined triggering :check(CurrentMaxBytesPerPixel <= PlatformSettingsBytes ...