Unreal Engine Issues

Consistent Crash using Cinematic Viewport on Linux

We are getting multiple crashes on 5.8.1 when trying to use the cinematic viewport on Linux, the most consistent way it's been reproduced is by clicking on the blue frame number to the left of the c ...

ImportMeshPaintTextureFromVertexColors only works with "Per Instance Vertex Colors"

The "Import Vertex Colors" feature in mesh paint mode only works if the instance had vertex color overrides enabled. This is especially problematic for Nanite meshes since usually you can't add act ...

Blueprint Independent Rig Modules fail to keep changes to public variables inside of Modular Rigs after closing and reopening the editor

The 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 ...

Navmesh not present for Mesh Partition terrain when using world partition navmesh builder

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Mutable COIs built from ChildCustomizableObjects are engine only but do not denote that in anyway.

When creating a Mutable setup with nested Child COs, COIs can result with Editor-Only references, which will cause the COI not appear in the build manifest and the appearance to now spawn in game. ...

Object with "defaultconfig" cannot be edited in Project Settings if their config section exists in DefaultXXX.ini

Notifies placed on the first frame of a montage using root motion don't fire

This is a regression in 5.8 caused by 47265321. It's because we now perform the montage update and dispatch the queued notifies via CharacterMovementComponent::TickCharacterPose.  But that all hap ...

Mover: based movement is unsupported/unsafe on async kinematic backends

Root motion extraction fails on blendspaces with bShouldMatchSyncPhases set

There’s a bug with the bShouldMatchSyncPhases codepath in UBlendSpace::TickAssetPlayer. That codepath calls ResetBlendSamples to give a deterministic output when advancing time on the animations ow ...

Editor crashes when overriding Texture Collection in Material Instance

When a Material uses the DefaultTextureCollection and a Material Instance overrides it - or vice versa - the Editor will crash. Note: bindlessconfiguration=Minimal or higher must be enabled to use ...