Unreal Engine Issues
Unreal Engine Issues
It is not possible to export virtual layer masks (AI or from mesh) through the COLMAP exporter.
RS - MVS - Jan 8, 2026Found in 2.1.0.119011 (R210). The mask export doesn't work even when the masks are regenerated from the mesh. Outcome: Error appears: "The filename, directory, or volume label syntax is incorrect ...
OverrideVertexColor causes a crash on mobile renderer
UE - Platform - Mobile - Jan 8, 2026Setting Allow CPU Access on the mesh, or setting bSupportsManualVertexFetch=1 in Engine.ini, avoids the crash. ...
Global Weight of Slot Node is incorrect when fetched after using a Pose Cache
UE - Anim - Runtime - Anim Blueprints - 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 ...
HDRIs do not appear in exported Presentations
TM - Core - Jan 7, 2026Reported in SF [Link Removed] HDRI environments are not appearing in exported Presentations. Occurs for both Local and Cloud exports and across all HDRI types. Thumbnails for Cloud Presentations w ...
FViewElementPDI::DrawLine calls for SDPG_World are not rendered in PIE or in Game
UE - Rendering Architecture - RHI - Jan 7, 2026When View.Family->EngineShowFlags.CompositeEditorPrimitives is false in the function RenderEditorPrimitivesForDPG. This code picks which version of the batched lines to renderconst FBatchedElements ...
Morph Targets fail to reset to zero
UE - Rendering Architecture - RHI - Jan 6, 2026"We have encountered a regression in UE 5.7 where Skeletal Mesh Morph Targets do not visually reset when all weights are set to 0.0. The mesh retains the deformation from the previous frame. This i ...
Out-of-Bounds Access During Partial Updates of ISMC Per-Instance Custom Data
UE - Graphics Features - Jan 6, 2026When using instance custom data values, removing an instance and changing the number of custom data floats in sequence can cause an array-out-of-bounds crash. The underlying arrays are not resized ...
CommonUI: FUITag, FUIActionTag variables can't connect with blueprint wildcard Equals node
UE - Editor - UI Systems - Jan 5, 2026Context UITag and UIActionTag are blueprint-exposed struct classes that derive from GameplayTag. GameplayTag variables can be compared in blueprint with ==. Under the hood, the node maps to UBlue ...
MultiProcessCook Shader Symbols fail to write when two workers race and try to write them at the same time
UE - Foundation - Data Pipeline - Cooker - Jan 4, 2026When shadersymbols are requested, cooking shaders writes the symbol files into {Project} /Saved/ShaderSymbols/<PlatformName>. These symbols are written by the function FShaderSymbolExport::Write ...
Buildgraph: "After" paramter on nodes doesnt add a dependancy
UE - Foundation - Horde - BuildGraph - Dec 22, 2025Adding the after parameter to a node, does not add a dependency like requires does. The documentation indicates that it would be triggered after another node. This was interpretated by the licensee ...