Unreal Engine Issues
Unreal Engine Issues
Ensure triggered inside Range Struct Customization when Property Node is no longer valid (e.g. when editing FFloatRange while FRuntimeFloatCurve editor is visible) [Ref.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 ...
Editor crashes if Timeline Play Rate node is copied/pasted in blueprints
UE - Gameplay - Blueprint - Jan 27, 2015Editor crashes when Timeline Play Rate node is copied/pasted. Frequency: 2/2 Crash Reporter: [Link Removed] Callstack: MachineId:4E82586D46B558EA69EF0EAA821297B1 EpicAccountId:1558531203f84e81 ...
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 ...
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 ...
Client Gameplay Effect stuck on due to duplicate ReplicationIDs
UE - Gameplay - Gameplay Ability System - Oct 31, 2025We've been tracking down a problem recently with the Gameplay Ability System where a gameplay effect is properly removed on the server, but the client has the gameplay effect stuck on permanently. ...
Mobile Previewer: Safe Zone Invalid Until Window Resize
UE - Platform - Mobile - Jul 12, 2021When the Mobile Previewer loads, the Safe Zone widget is not working properly at startup, and requires a window resize to update to the correct Safe Zone. ...
[AI] Gaps between Nav Mesh tiles in World Partition map causing movement issues
UE - AI - Navigation - Nov 4, 2025Navmesh has seams between some tiles that are actual edges rather than previously found "gaps" where it was a debug rendering issue. Pathfinding does fail between these tiles to go straight across. ...
[CrashReport] Mac crash - UE4Editor-Slate.dylib!FTextLayout::GetAsTextAndOffsets()
UE - Platform - Apple - Aug 15, 2017This is a trending Mac crash in 4.17.0 that also had some occurrence in 4.16. Users have not provided any descriptions of their actions when the crash occurred, but the callstack is nearly identica ...