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] ...

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

UE - Runtime - Character - 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. ...

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, 2015

Performing 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, 2017

This 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 ...

Crash in GC - FSharedStruct reachability race condition

UE - Core - Systems - Jul 13, 2026

This Jira was created from the linked EPS case: =============================================== This issue is caused by FSharedStruct batching reachability requests to the same underlying FInstan ...

When PCH is Disabled, Error Occurs in VulkanGenericPlatform.h at Android Build

UE - Graphics Features - Dec 6, 2018

If disable PCH in Target.cs, an error will occur when building for Android. The log is as follows. LogPlayLevel: Error: D:/Build/Release-4_21_0/Engine/Source/Runtime/VulkanRHI/Private/Android/../Vu ...

CRITICAL: Regression: CRASH: SHOOTERGAME: Client crashes when using ServerTravel command

UE - Networking - Sep 17, 2014

Update (5/4/15): New repro steps using Main (//depot/UE4/Promotable-CL-2535351): 1. Create a new Blueprint project 2. Create 3 new Levels: MainMenu, Lobby, and Level 3. Create 3 new GameModes: Main ...

Subobject delimiter replacement in ResolveName can cause previously valid strings to exceed NAME_SIZE

UE - Core - Systems - Nov 8, 2021

ResolveName will replace the subobject delimiter (colon) with two periods. This increases the length of the string, and can cause asserts due to the string exceeding NAME_SIZE even when the name was ...