Unreal Engine Issues
Unreal Engine Issues
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 ...
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 ...
Bake To Control Rig produces empty keys when rig uses Import Skeleton in Construction Event and binding is a spawnable in a subsequence
UE - ACT Character - Control Rig - Aug 28, 2026Bake To Control Rig fails to key procedurally-created controls when all three of the following are true:The Control Rig creates its hierarchy at runtime via Import Skeleton in the Construction Event ...
Blueprint Independent Rig Modules fail to keep changes to public variables inside of Modular Rigs after closing and reopening the editor
UE - ACT Character - Control Rig - Aug 11, 2026The problem is that when adding modules in modular control rig, I can not change values for module variables - as soon as I close and reload the Unreal Editor, values snap back to default values. I ...
Deadlock during cooking or editor in URigHierarchyController::AddElement on task thread while GarbageCollection occurs on gamethread.
UE - ACT Character - Control Rig - Apr 15, 2026In URigHiearchyController::AddElement (and other functions), arbitrary delegate code is called while holding Hierarchy->ElementsLock, through the Notify function. URigHierarchy::AddReferencedObject ...
Renamed controls creating duplicate curves in sequencer that once fixed up cause selection issues.
UE - ACT Character - Control Rig - Mar 25, 2026When a control is renamed after it has already been animated in a sequence, the control curve name map needs to be fixed up. Once it is fixed, selecting the control in the world will not map the sel ...
Modular rig - Hindleg thigh bug when switching from IK to FK
UE - ACT Character - Control Rig - Mar 16, 2026The thigh FK controller of the hingleg in modular rig doesn't move the thigh bone, causing bad deformation on the mesh around character's thigh area. ...
Control Rig compile issue - Re-Entry of Instructions
UE - ACT Character - Control Rig - Jan 8, 2026Compiling a specific graph construction generates a compile error and blocks the execution of the graph. Sync to AnimSandbox CL 49645845 See attached picture and attached Control Rrig asset ...
Provided example Control Rig Python scripts that feature calls to GetControlRigBlueprint need to be updated to GetControlRigAssetInterface.
UE - ACT Character - Control Rig - Dec 9, 2025The unreal.ControlRigContextMenuContext.get_control_rig_blueprint() this function has been deprecated in Unreal Engine 5.7. As a result, the Python scripts included with the Control Rig plugin no ...
Morph target is not applied on the first frame in Level Sequence
UE - ACT Character - Control Rig - Dec 4, 2025When a skeletal mesh with morph targets spawns in the sequence, the morph is not reflected in the first frame. In the ProcessStage_SkinCache call of SkeletalMesh, MorphVertexBuffer->SectionIds is ...