Unreal Engine Issues
Unreal Engine Issues
Sequencer : Attaching a Possessable to multiple Spawnables across multiple cuts causes incorrect location restoration
zComponent - Archive - Nov 12, 2021Regression No, according to affects versions 4.27 and 4.27.1 The restore process proceeds in the following order : 1. Remove spawnable actor in first cut (no effect because the actor is already r ...
"FVector contains NaN" on packaged builds for Debug configuration
UE - Graphics Features - Lumen - May 6, 2022Customer Provided Description:This was experienced in UE 5.01 - custom installed engine (No changes to UE code, simply added the Debug build configuration, see the following command): "c:%ue_dire ...
Crash handling: Prevent reports of assertions during shutdown after an assertion
UE - Core - Systems - Aug 8, 2024CriticalErrors in FWindowsErrorOutputDevice::Serialize (and other platforms) run some code after the error is detected rather than immediately terminating the process. Some of this other code is spe ...
LoadErrors:Warning: Warning CreateExport: Failed to load Outer for resource when moving Blueprints folder to another folder
UE - Gameplay - Blueprint - Apr 14, 2017There are 3 assets from Content > Blueprints > Missing Types that are failing to be moved over The assets are causing the warnings are:BP_NodeClassIsMissingBP_ParentClassIsMissingTypeBP_PinReferenc ...
Actors disappearing after saving a large number of modifications to world partition maps
UE - Editor - Nov 4, 2022From Licensee: "We've encountered a world partition bug where newly created actors go missing in the viewport and Outliner after saving modifications to a large number of actors. This bug is partic ...
Users are unable to create projects when the default project location is a networked drive
UE - Editor - Oct 23, 2024There have been multiple reports of this issue, particularly from schools, over the last 10 years:https://forums.unrealengine.com/t/invaild-folder-path-with-network-user-drives/283475https://forums. ...
LevelStreamingPersistence: BP added components don't persist properties in PIE until map actor resave
UE - World Creation - Worldbuilding Tools - Mar 6, 2026Context The LevelStreamingPersistence plugin can be used to remember and restore properties on actors, components and other objects that are part of a streamed level. Persisted properties are resto ...
LayeredBlendPerBone without BlendRootMotionBasedOnRootBone exaggerates root motion
UE - Runtime - Animation - May 27, 2023When BlendRootMotionBasedOnRootBone is false, the LayeredBlendPerBone is aggregating root motion of the child poses ontop of the base pose root motion. (ie. if the first child pose's blend weight i ...
Copying a grouped MaterialInstanceParameterDetail property that has spaces on it's name does not enclose it in double quotes, and later pasting won't work as expected
UE - Rendering - Architecture - Materials - Aug 24, 2025Copying a grouped MaterialInstanceParameterDetail property that has spaces on it's name does not enclose it in double quotes, and later pasting won't work as expected. The licensee noticed this in a ...
Niagara Mesh Renderer registers NumParticles x NumMeshVariants TLAS instances
UE - Rendering - Graphics Features - Ray Tracing - May 28, 2026When using the Niagara Mesh Renderer with multiple mesh variants selected via MeshIndex, the number of TLAS instances allocated is NumParticles × NumMeshVariants and enabling the Path Tracer can ca ...