Unreal Engine Issues
Unreal Engine Issues
Second UVs wiped when using Merge Actors Tool
UE - World Creation - Worldbuilding Tools - HLOD - Jan 26, 2017The merge actor tool no longer saves additional UVs used for the merged mesh. This was not the case in 4.13, but in 4.14 and later this information is no longer present. Also worth noting is that i ...
Control Rig: crashes when compiling after rearranging input pins in an array in Example Rig Unit
OLD - Anim - Aug 20, 2019The crash doesn't occur every time, but it will happen within 3 swap and compiles in my experience. I got multiple different callstacks when I cause the crash using the reproduction steps (they are ...
Failed to generate Nanite data for mesh with bDoFastBuild enabled
UE - Graphics Features - Nanite - Oct 1, 2025If "bDoFastBuild" is enabled on a Static Mesh asset, in-editor it will never be able to have Nanite data built for it, preventing the Static Mesh from using Nanite. There is no way to fix this issu ...
Packaging Error When Setting Recast Nav Mesh Runtime Generation
UE - AI - Jan 25, 2016Setting the Runtime Generation on the Recast Nav Mesh to a different preset than what is set in the Project Settings causes an error to appear upon trying to package the project, and causes the pack ...
Project Crashes on Open when Implementing An Interface and Its Duplicate
UE - Gameplay - Blueprint - Apr 25, 2016The linked project crashes on open after attempting to implement an interface and a duplicate of that same interface with different function names. This has not been reproduced in a clean project, h ...
Editor ensure in USceneComponent::OnComponentDestroyed during Blueprint compilation GC
UE - Framework - Components - Jan 15, 2026An editor-only ensure can trigger during BP compilation when garbage collection cleans up transient components created as part of component replacement. During recompilation, old component instances ...
WorldPartition RuntimeHashSet: non-deterministic URuntimePartitionPersistent UObject name causes unstable Cooked output (RuntimePartition:DebugColor)
UE - World Creation - Worldbuilding Tools - HLOD - Jul 9, 2026During deterministic Cook / Package validation, the Cooked output of a WorldPartition map was found to vary non-deterministically between Cook runs. Diff detected in the DiffOnly Cook log:Serialize ...
Crash when using Set Collision Response on a Destructible component
UE - Simulation - Physics - Destruction - Dec 20, 2016Crash when using Set Collision Response on a Destructible component. The repro is using the Construction Script but this also happens using Event Begin Play in the Event Graph on play. It crashing ...
[CrashReport] UE4Editor_Renderer!FUniformMeshConverter::Convert()
UE - Graphics Features - Aug 3, 2017This is a regular crash that has occurred through 4.16 and into the 4.17 previews. The callstack is similar to [Link Removed] (invalid), although the error message is different. User Description ...
Crash when resizing window using Quad Stereo Buffer
UE - Virtual Production - nDisplay - Oct 2, 2019We noticed crashes in our application when we attempted to resize a window or switch to full-screen mode. Hence, resizing windows and switching to full screen will result in a crash on Unreal Engine ...