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 ...
Ensure triggered inside Range Struct Customization when Property Node is no longer valid (e.g. when editing FFloatRange while FRuntimeFloatCurve editor is visible) [Ref.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 - UI Systems - Nov 12, 2025[Link Removed] was fixed by CL 46990575, successfully avoiding an ensure condition inside FIntervalStructCustomization::SetValue() when its Property Node is no longer valid. However, the same proble ...
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 ...
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 ...
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. ...
[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 ...
Mover Plugin: UNavMoverComponent::GetFeetLocationBased() returns incorrect FBasedPosition when using WalkingMode over a Movable floor, making UPathFollowingComponent erroneously detect a blocked move
UE - Gameplay - Player Movement - Mover - Nov 12, 2025Function UNavMoverComponent::GetFeetLocationBased() on file "NavMoverComponent.cpp" returns an FBasedPosition built from an FRelativeBaseInfo. The "MovementBaseInfo" is read from key "CommonBlackboa ...