Unreal Engine Issues
Unreal Engine Issues
Iris - removal of fast array item not performed on client when server array contains a non-replicated item
UE - Networking - Iris - Sep 8, 2025It is possible to add items to a replicated fast array that are not intended to be replicated to the clients. For example, FGameplayAbilitySpecContainer has a custom ShouldWriteFastArrayItem impleme ...
Crash when changing r.MaterialQualityLevel when FastGeo plugin enabled in cooked build
UE - World Creation - Worldbuilding Tools - Sep 5, 2025The engine crashes when the r.MaterialQualityLevel is changed in a cooked game that uses the FastGeo Streaming Plugin. The crash doesn't repro with the same steps in Editor, just in a cooked build. ...
'Malformed sequence hierarchy' ensure hit after modifying sub-sequence tracks
UE - Anim - Sequencer - Sep 5, 2025It's possible for there to be multiple instances of the same sequence in the evaluation states cache if the same sequence is used in multiple sub-sections. Caches are never removed from the evaluat ...
Client and server can both get stuck waiting for packet sequence history flush
UE - Networking - Sep 4, 2025The issue occurs when both instances have a significant difference between their last sent and last ack'd sequence number, as they will begin waiting for the sequence history to be flushed for a pac ...
MRQ - Subgraphs do not evaluate properly in Quick Render
UE - Virtual Production - Tools - MRQ - Sep 4, 2025Subgraphs do not seem to be evaluating properly with Quick Render. Message from the EPS: "While testing out Quick Render, I've found that subgraph nodes are not being evaluated. Digging into it dee ...
Find in Blueprints: Default values of TMap keys are not returned
UE - Framework - Blueprint Editor - Sep 3, 2025Context Find-in-Blueprints can be used to search the current, or all, blueprints. If you enter a simple string, it would return nodes, pins, pin default values and default values for BP Variables ( ...
PoseSearch Query is flipped 180 degrees 1 frame after a capsule/actor rotation happens.
UE - Anim - Gameplay - Sep 3, 2025Using MotionMatching with a PoseSearchSchema with a Trajectory grouping. The query gets rotated to match the capsule/mesh component instead of the offset root/actual location of those bones/trajecto ...
RigVMRegistry : The registry is not locked for writing yet : ensure statement error during cook
UE - Anim - Rigging - Control Rig - Sep 2, 2025I am seeing an cook failure at the very beginning. It goes away with a retry step via Horde. Please find attached call stack. I am able to consistently reproduce it by wiping all the DDC cache and ...
Precision issues with 16-bit Skin Cache shaders.
UE - Rendering Architecture - Sep 2, 2025A licensee reported precision issues with position in the gpu skin cache shaders with 16-bit real types enabled. ...
When ControlRig.EnableAnimNodePerformanceOptimizations is enabled, the default pose briefly appears after the Control Rig is reinitialized
UE - Anim - Rigging - Control Rig - Sep 1, 2025Since UE5.6, ControlRig.EnableAnimNodePerformanceOptimizations is enabled by default, and this appears to be causing the issue. Specifically, when the control rig’s construction event is processed, ...