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 ...
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 ...
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 - Rendering - Architecture - Shaders - 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 ...
When r.SSR.Stencil is enabled, there is wrong logic observed.
UE - Rendering - Graphics Features - Dec 19, 2025When r.SSR.Stencil is enabled, the areas with high roughnesss are not discarded and Unlit materials are incorrectly handled. See the linked EPS case (Additional Info URL) for a full explanation of ...
Crash when a StateTree-related Parameter is of a type that includes two nested arrays with the same name (due to FPropertyChangedEvent::ArrayIndicesPerObject using array names to map to their changed indices)
UE - Framework - Dec 19, 2025This issue was reported in the context of adding and setting parameters on StateTrees, Tasks and related assets, but its root cause lies in the structure FPropertyChangedEvent and can possibly affec ...
Crash during .zfprj import when Feature detection quality is set to High and Use mosaic images as feature source is set to Yes
RS - Alignment - Dec 19, 2025Found in 2.0.0.118621 (R200). It appears that the combination of Feature detection - High and Use mosaic images as feature source during .zfprj LiDAR import - Yes. causes a crash. Outcome: RS ...
Call In Editor functions not working in blueprints
UE - Editor - Developer Usability - Dec 19, 2025Context When selecting a component on an actor, any CallInEditor functions on the component's class appear as buttons in the details panel. Problem The CallInEditor functions don't execute in Blu ...