Unreal Engine Issues
Unreal Engine Issues
ShouldMarkSyncPhases causes pose discontinuities when sync leader changes
UE - Runtime - Anim BP - Aug 27, 2026The issue is caused by the way that we calculate the leader sample's Time vs the follower sample’s Time and how that calculation switches on the frame when a follower sample becomes a lead sample. ...
Layered Blend Per Bone nodes evaluate to 0.0 weight with Blend Masks when s.AsyncLoadingThreadEnabled is active in Editor
UE - Runtime - Anim BP - Aug 11, 2026When starting the Editor, Layered Blend Per Bone nodes using Blend Masks inside dynamically linked Anim Layers completely ignore the blend pose (evaluating to 0.0 weight for all bones). Disconnectin ...
Functions referenced via a Property Access node don't appear in blueprint Find By Class Member results
UE - Runtime - Anim BP - May 22, 2026Finding Reference By Class Member fails to find references to bp functions from property access nodes. ...
Property Access nodes fail to display variable data in SM transition tooltips
UE - Runtime - Anim BP - May 22, 2026The data shown in the transition tooltip is generated via SKismetLinearExpression::MakeNodeWidget. The issue is that while UK2Node_VariableGet have specific functionality to display the variables a ...
AnimNode content is not applied during PIE when s.AsyncLoadingThreadEnabled is enabled
UE - Runtime - Anim BP - Mar 16, 2026When the following setting is added to DefaultEngine.ini, the AnimNode content is not applied during PIE execution.[/Script/Engine.EditorStreamingSettings] s.AsyncLoadingThreadEnabled=True If the A ...
Animation compression deadlock
UE - Runtime - Anim BP - Feb 5, 2026The deadlock occurs when attempting to cancel compression during animation sequence destruction. The compression thread ends up deadlocking with the game thread, which is the one requesting the canc ...
Global Weight of Slot Node is incorrect when fetched after using a Pose Cache
UE - Runtime - Anim BP - Jan 7, 2026When a montage slot node output is pushed to a Pose Cache and used in a Two-Way Blend, the value returned by GetSlotNodeGlobalWeight will be the current fractional value rather than the actual globa ...
Editor localization causes the GetLinkedAnimLayerInstanceByGroup function to fail in retrieving the corresponding LinkedAnimLayer within the editor.
UE - Runtime - Anim BP - Dec 18, 2025When using other language(such as Chinese) as editor language, the Group Name of the Animation Interface will be localized to Chinese. In editor, the animation blueprint grab the group from metadata ...
Recompiling an ABP that another ABP has a Property Access dependency on without recompiling/linking the other causes a crash
UE - Runtime - Anim BP - Oct 2, 2025The 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
UE - Runtime - Anim BP - Sep 24, 2025When 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 ...