Unreal Engine Issues
Unreal Engine Issues
Bug - Vertex Interpolator exposing parameters to instance even if its not connected
UE - Rendering - Architecture - Materials - Feb 17, 2026Parameters attached to the input of a Vertex Interpolator Material Expression are visible in the Material Instance, even if the output of the Vertex Interpolator Material Expression is not connected ...
Non-deterministic actor names created by ChildActorComponent if level uses OFPA
UE - Framework - Blueprint - Feb 16, 2026The bug only happens when the ChildActorComponent is added to the BP after placing instances and saving the world. Adding the ChildActorComponent after this will result on the name of the child acto ...
Distance Field Shadows do not work with Nanite meshes
UE - Rendering - Graphics Features - Nanite - Feb 16, 2026Nanite meshes only cast virtual shadow maps and do not cast any distance field shadows, regardless of the distance of the shadow casting mesh to the camera. ...
Directly opening a modified map asset of a streaming sublevel does not always force it to be reloaded (inconsistent with other map open behaviors)
UE - World Creation - Worldbuilding Tools - Feb 10, 2026When the level currently being edited has unsaved changes and the user opens a new one, the Editor asks if the changes should be saved. If the user answers negatively, the level asset is reverted to ...
Client disconnected due to MissingLevelPackage in editor with Iris and server streaming enabled
UE - World Creation - Worldbuilding Tools - World Partition - Feb 9, 2026When connecting to the server, if the client activates some local cells while the connection is still pending, ULevelStreaming::IsConcernedByNetVisibilityTransactionAck will return false. In this ca ...
Missing logging or error when applying an anim instance to a skeleton that the anim instance doesn't match.
UE - Runtime - Animation - Feb 9, 2026Currently, we detect whether an anim instance is supported by the skeletal mesh and, if it isn't, unreference the instance, but we don't error or warn the user that this happened. This leads to conf ...
Using PCG, StaticMeshComponentPropertyOverride only takes effect when the flag ExecuteOnTheGPU is off.
UE - World Creation - Procedural Tools - Feb 9, 2026StaticMeshComponentPropertyOverride only takes effect when the flag ExecuteOnTheGPU is off. All error checking for StaticMeshComponentPropertyOverride turns off when the flag ExecuteOnTheGPU is off ...
Landscape HLODs are broken in 5.7.2 (Github Release branch)
UE - World Creation - Worldbuilding Tools - HLOD - Feb 6, 2026Landscape HLODs are broke when build from Editor. See repro steps above. I have not provided a repro project as it uses the open world starter map. Note that current Main has additional bugs that o ...
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 ...
Approximate HLOD: Default materials are not compatible and get rejected by FMaterialUtilities::IsValidFlattenMaterial when forcing their use
UE - World Creation - Worldbuilding Tools - HLOD - Feb 3, 2026The Approximated Mesh HLOD layer cannot use its default materials: FullMaterialBakeOutputMaterial_PackedMRS and FullMaterialBakeOutputMaterial. The Param2D names are incompatible and the materials ...