Unreal Engine Issues

Deadlock in UAnimationSequencerDataModel::Evaluate where FScopeLock Lock(&EvaluationLock) blocks execution indefinitely

When both the Sequencer Editor and an Animation Curve Editor are open for the same animation asset, the editor freezes completely upon editing the curve. Analysis indicates that the freeze is caus ...

Uploading of the SBT via copy queue is not guaranteed to be synced with async compute queue but only direct queue in d3d12

When HitLighting is enabled, SBT commit is running on the Graphic Queue, and the pass "LumenSceneLighting->offscreenshadows->LumenDirectLightingHardwareRayTracingRGS" that uses SBT could run on the ...

[5.6 bug] FbxImportUI settings physics_asset configuration appears to have no effect

My fbx import script that used to work in 5.4 stopped creating physics asset when ran in 5.6 i checked the api and doesnt seem like it has changed between the two versions. below is the fbx import s ...

Body Setup of a Static Mesh with Simple Collision will pass validation, but removing it and using only a Complex collision and setting Collision Complexity "Use Complex as Simple" will fail validation: "Bone None requires at least one collision shape".

Context: By default, Unreal Engine creates both simple and complex shapes, then, based on what the user wants (complex query versus simple query), the physics solver will use the corresponding shape ...

[Interchange] FBX - Front Facing X-Axis and Flipped Bone Orientation During Animation

Actors attached to a skeleton imported through a FBX file with the Front Facing X-Axis option enabled are flipped when the skeleton is animated. ...

Intermittent Content is Missing from Cook errors for objects with Niagara packages

Intermittently when cooking large licensee projects, an error is reported at the end of the cook:LogCook: Error: Content is missing from cook. Source package referenced an object in target package b ...

Lightmass CalculatePointShadowing regression in UE5.6

There is a regression or change in the Build Lighting process when using Lightmass in Unreal Engine 5.6:When building lighting with Lightmass calling the CalculatePointShadowing function, the result ...

If a mesh contains more than 32 material slots, it can cause a hash collision when computing the Raytracing CachedMeshCommandHash

Recompiling an ABP that another ABP has a Property Access dependency on without recompiling/linking the other causes a crash

The crash comes from the pointers in FAnimSubsystem_PropertyAccess::Library::Indirections in the layer ABP from pointing to old/invalid functions and properties from the trash ABP_Manny, as they hav ...

Post Process Animation Blueprint Crash When Using Blend Node

When using a Blend node inside a Post Process Animation Blueprint, the editor crashes while rendering thumbnails. The crash occurs because USkeletonThumbnailRenderer attempts to draw a thumbnail wit ...