Unreal Engine Issues
Unreal Engine Issues
"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 ...
[CrashReport] UE4Editor_CoreUObject!StaticAllocateObject() [uobjectglobals.cpp:2153]
UE - Anim - Sequencer - Jun 3, 2016Really close to the repro steps for [Link Removed] Same repro steps produced the following Buggs along with this one: [Link Removed] [Link Removed] Error message: Fatal error: [Link Removed] [Lin ...
Actors disappearing after saving a large number of modifications to world partition maps
UE - Editor - Workflow Systems - 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 ...
Incorrect behavior after attaching an actor to a non-root component of another actor in the Editor
UE - Editor - Workflow Systems - Jul 3, 2024UE allows actors to be attached to other actors. More precisely, it allows the root component of an actor (child) to be attached to any component of another actor (parent). From now on, "parent" and ...
Ensure triggered inside Range Struct Customization when Property Node is no longer valid (e.g. when editing FFloatRange while FRuntimeFloatCurve editor is visible) [Ref. UE-341339]
UE - Editor - Workflow Systems - Nov 12, 2025[Link Removed] Closed was fixed by CL 46990575, successfully avoiding an ensure condition inside FIntervalStructCustomization::S ...
Half precision is not supported for OpenGL ES 3.1 Pixel Shaders
UE - Platform - Mobile - Apr 6, 2018Fix the cross compiler so half precision is supportedAdd a project setting to specify the default precision to support on ES31. Be sure the shader version takes this setting into account. — User des ...
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 ...
[CrashReport] Crash on Mac related to cooking for IOS
UE - Graphics Features - Jul 20, 2017This is a common commandlet crash for Mac users in 4.16. In all cases, the command line is like: "(path/project).uproject" -run=Cook -NoLogTimes -TargetPlatform=IOS -fileopenlog -unversioned -ski ...
LayeredBlendPerBone without BlendRootMotionBasedOnRootBone exaggerates root motion
UE - Anim - Runtime - 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 ...
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 ...