SCS child scene component instances can be registered out-of-order with non-scene component instances (regression).

UE - Gameplay - Components - Sep 7, 2016

This behavior is a regression in 4.12. Essentially we switched to attaching child components as part of the OnRegister() logic. This caused all root-level SCS components (including non-scene compone ...

[CrashReport] Commandlet crash in UE4Editor_CoreUObject!UPackage::Save

UE - Foundation - Core - May 2, 2016

This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Error message: Assertion failed: Pair != nullptr [Link Removed] [Line: 520] Source Context:4 ...

Crash when attempting to convert a sequencer actor into a BP Class

UE - Anim - Sequencer - Nov 15, 2016

Error message: Assertion failed: IsValid() [Link Removed] [Line: 752] Source Context: 738 return *this; 739 } 740 741 /** 742 * Converts a shared ...

[AI] StateTreePropertyRef does not have option for Promote to Parameter

UE - AI - StateTree - Nov 5, 2025

I got a report from one of my designers that since we took 5.6, they have been unable to see the "Promote to Parameter" options when attempting to bind an output from one of our common tasks. I took ...

UFE Deploying and launching a packaged build on Linux fails due to invalid directory

UE - Platform - Linux - Dec 22, 2016

Deploying and launching a packaged project, using a Custom Launch Profile that is set to copy the project to a repository, fails due to a missing /. I do not see this issue when running a Quick Lau ...

"Save Current As" is not fully loading the newly-saved level

Tools - Mar 15, 2017

Workaround: Navigate to and open the newly-created level in the Content Browser prior to LaunchOn. After using the Save Current As tool, Game runs into error when trying to LaunchOn. Editor display ...

[CrashReport] UE4Editor-Renderer.dylib!FSceneRenderTargets::GetGBufferResourcesUniformBuffer()

UE - Graphics Features - Jul 20, 2017

This is a common crash affecting Mac users on 4.15 and 4.16 User Descriptionswhen i activate the blur effect of chameleon plugin. From LogAssertion failed: Assertion failed: IsValidRef(GBufferReso ...

[AI] Navmesh does not generate correctly on a plane that has a slope of 45 degrees or more.

UE - AI - Navigation - Sep 23, 2022

Navmesh generation appears to have issues handling terrain and planes that are at 45 degree or steeper angles even if the agent max slope is set to allow for such movement. While the issue occurs at ...

[AI] BehaviorTreeEditor crash when swapping from Behavior Tree to Blackboard view.

UE - AI - BehaviorTree - Aug 24, 2023

The first time that a Behavior Tree editor window changes from the tree to the Blackboard can cause a crash if you add and remove a key from the Blackboard via a different Behavior Tree editor windo ...

Editor Crashes when copy/pasting an emitter in the Niagara timeline

UE - Niagara - Feb 8, 2023

When creating the emitter's track widget we search for the stack view model's root entry, but the stack view model pointer is null, so we crash.  ...