Unreal Engine Issues
Unreal Engine Issues
[CrashReport] Crash on Mac due to uncaught exception 'NSRangeException' - NSCFConstantString characterAtIndex
UE - Platform - Apple - Jul 27, 2017This is a common and longstanding community crash on Mac. Users have not provided descriptions when they crash, so additional information is currently not available. A log file is attached. Callsta ...
[Enhanced Input] Chord trigger fails when its referenced action lives in a lower-priority IMC
UE - Gameplay - Input - May 18, 2026Summary 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, 2017This 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 ...
Crash in editor after disabling AISystem in Worldsettings
UE - AI - May 16, 2018After disabling the World Option bEnableAISystem, clicking with the right mouse button on the asset browers (in an empty place) casues the editor to crash. ...
Ensure condition failed : SkeletalMeshLocation module on scaled SkeletalMesh
UE - Niagara - Jul 14, 2020The 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, 2021Repro from licensee here - [Link Removed] ...
Mover | FStanceModifier adjustment teleport on Crouch/Uncrouch can fail when child components intersect world
UE - Gameplay - Player Movement - Mover - Feb 3, 2026Context 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, 2016This 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. ...
Performing a Hot Reload after changing a custom component code class can make the component unusable in Blueprints, or crash the Editor.
UE - Gameplay - Blueprint - Feb 19, 2015Performing a Hot Reload after altering a custom component code class can make the component unusable in Blueprints, and even crash the Editor. WORKAROUND: Close and re-open the Editor. ...
[CrashReport] UE4Editor_LevelEditor!FLevelEditorActionCallbacks::Paste_CanExecute() [leveleditoractions.cpp:1602]
UE - Gameplay - Blueprint - Jan 17, 2017This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Descriptions from users are provided below. Error message: Assertion failed: GEditor->GetSele ...