Unreal Engine Issues
Unreal Engine Issues
Crash Upon Sequencer Modification of Actor's Array Variable
UE - Anim - Sequencer - Dec 7, 2018If Sequencer event track modifies an Actor's Integer Variable Array that is exposed to Cinematics, the Editor will crash when the Stop button is pressed. ...
macOS build appears to hang due to UBT deadlocking on ps buffer
UE - Foundation - Cpp Tools - Apr 22, 2021Licensee reports buffer deadlock issue in System/BuildHostPlatform.cs (lines 283-329). Moving Proc.WaitForExit() to after the for-loop seems to resolve the issue for them.publicoverride ProcessInf ...
Crash in blueprints when opening right-click menu
UE - Gameplay - Blueprint - Apr 22, 2015Right clicking inside the event graph of a blueprint that is derived from PhysicsCollisionHandler will crash the editor CrashReporter: [Link Removed] ...
OnComponentWake Event does not trigger when the physical body is awoken by a Force
UE - Runtime - Simulation - Feb 27, 2025OnComponentWake Event does not trigger when the physical body is awoken by a Force. The steps described on Steps To Reproduce is enough to replicate this behavior. The OnComponentWake event is only ...
Crash occurs when opening a Blueprint that contains a variable that is of a type of a child of the Blueprint, as well as a component containing instanced UObjects
UE - Gameplay - Blueprint - Dec 23, 2016A crash that is possibly the result of a circular dependency can occur if a Blueprint containing an ActorComponent with instanced UObjects and a variable that is a type of a child of itself is opene ...
"Primitives with unbuilt interactions" not clearing after lighting scene rebuild
UE - Rendering - Features - Oct 29, 2021Regression No, according to affect version 4.26 and 4.27 [2021.10.29-17.01.06:085][830]Primitives with unbuilt interactions: 6[2021.10.29-17.01.06:085][830] Primitive FoliageInstancedStaticMeshComp ...
Paper2D: Editor hangs when assigning Sprite Atlas Group to Sprite
UE - Gameplay - Paper2D - Dec 16, 2025In UE 5.3 and later, assigning a Sprite Atlas Group to a UPaperSprite asset can cause the editor to hang and eventually crash. This behavior has been reproduced in 5.3, 5.6, and a recent UE5-main so ...
Frame-locked sequencer intermittently triggers notify state end event
UE - Runtime - Animation - Mar 10, 2026Frame-locked Sequencers can occasionally produce frames with a zero delta time due to frame number truncation. When this occurs, if the animation cursor is within the range of a Notify State that is ...
RemoteMac.cs fails to build if ProjectFile is null
UE - Platform - Mobile - May 17, 2019See CL 6473818. Remote compiling on a Mac is triggering a NullReferenceException for me, making me unable to build. I was able to delete the crashing lines locally to work around it for now.line 91 ...
Multiple Materials not assigned to Mesh on Import
UE - Editor - Content Pipeline - Import and Export - Jan 6, 2017Not all material elements are created and assigned to the static mesh using multiple materials. With the attached mesh, only the first element is created and the other two are left non-existent. I c ...