[Enhanced Input] Chord trigger fails when its referenced action lives in a lower-priority IMC

UE - Gameplay - Input - May 18, 2026

Summary A UInputTriggerChordAction does not fire when the action it references (the "chording action") is mapped in a different Input Mapping Context with a lower priority than the IMC containing the ...

[CrashReport] Assertion on Mac in FCocoaRunLoopSource

UE - Platform - Apple - Jun 14, 2017

This is a common crash among Mac users in 4.16. It is spread out among many separate CrashGroups, with slight variations in Callstack. Some Example CrashGroups [Link Removed] [Link Removed] [Link ...

[CrashReport] Mac crash - USpeedTreeImportFactory::FactoryCreateBinary()

Tools - Sep 8, 2017

This is an infrequent Mac crash that has occurred for a few users since at least 4.16. Users have not provided any descriptions of their actions when the crash occurred. The callstack shares simil ...

StateTree: While editing State Parameters or exposed properties of a Condition/Task, an ensure() fires when editing inputs of a Property Function bound to an array element

UE - AI - StateTree - Mar 5, 2026

Consider an array property that can be edited in the StateTree editor. This can be a State Parameter or an exposed property of a Condition or Task, for example. Each element of the array can be boun ...

CPF_TextExportTransient and RF_TextExportTransient inconsistent behavior

UE - Framework - Blueprint - May 23, 2024

The TextExportTransient can be specified as a property flag and object flag. Behavior is inconsistent: there are many ways in which an object marked TextExportTransient can still be part of the text ...

Ensure condition failed : SkeletalMeshLocation module on scaled SkeletalMesh

UE - Niagara - Jul 14, 2020

The message in ensure is below LogOutputDevice: Error: === Handled ensure: === LogOutputDevice: Error: Ensure condition failed: (FMath::Abs(1.f - M.GetScaledAxis(EAxis::X).SizeSquared()) <= (1.e-4 ...

Crash in MaterialInstance when deleting a layer

UE - Graphics Features - May 4, 2021

Repro from licensee here - [Link Removed] ...

Breaking a level instance can not remove the level instance from world

UE - World Creation - Worldbuilding Tools - Level Instances - Nov 5, 2024

Currently there is no stable way to break level instances ...

Mover | FStanceModifier adjustment teleport on Crouch/Uncrouch can fail when child components intersect world

UE - Gameplay - Player Movement - Mover - Feb 3, 2026

Context When crouching and uncrouching with Mover’s DefaultMovementSet, the pawn capsule’s half height is changed. This behavior mimics the CharacterMovementComponent. To ensure the pawn’s feet sta ...

AttachRootComponentToActor being used over a network can cause an Ensure (previously an Assertion) to be triggered.

UE - Gameplay - Jan 11, 2016

This is a continuation of [Link Removed]. The previous ticket changed an Assertion to an Ensure in order to stop a crash from occurring, and stated that a more complete fix would be coming in 4.10. ...