Unreal Engine Issues
Unreal Engine Issues
Editor crash when adding mesh renderer elements in Niagara
UE - Niagara - Jul 8, 2025When adding multiple meshes to a Niagara Mesh Renderer Module, a check() will be triggered due to a mismatch in the number of Widgets and the number of Tooltip Widgets. ...
[CrashReport] UE4Editor_Engine!ULevel::GetWorldSettings() [level.cpp:1781]
Tools - Aug 22, 2016This 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: WorldSettings != ...
Niagara color picker user parameter preview no longer updates until confirmation
UE - Niagara - Apr 18, 2025Starting with UE 5.4, the Color Picker Tool no longer updates preview values in real time for certain editor windows like Niagara when working with User Parameters. This behavior is a regression fr ...
Crash on iOS9 when using Apple's CFNetwork library
UE - Platform - Mobile - Dec 6, 2016Many clients have hit a crash due to an Apple library using operator delete on a memory block that was not allocated with operator new. This happens with the following callstack on iOS9 in UE4.13 o ...
Behavior Tree (BT) services added to root nodes call the initial tick twice
UE - AI - Nov 20, 2024Behavior Tree (BT) services added to root nodes call the initial tick twice A BT Service with the setting "Call Tick on Search Start" enabled will execute the initial tick twice when added to the ro ...
Crash when returning to viewport from immersive mode with an editor window tabbed beneath
Tools - Mar 2, 2015When the user enters immersive mode by hitting f11 and then opens the material editor, (which opens tabbed in the editor underneath the immersive display)The engine crashes when hitting attempting t ...
BuildPatchTool crashes on Mac and Linux when building android or ios with multiple chunks
Portal - Feb 18, 2020"It seems that deallocation of TLazySingleton<FInternationalization> causes unhandled exception. If DISABLE_LAZY_SINGLETON_DESTRUCTION=1 is provided - the build completes successfully" ...
Editor crashes due to a material that contains MPCs migrated from another project
UE - Rendering Architecture - Materials - Apr 29, 2024[2024.04.29-16.49.46:563][970]LogUObjectGlobals: Warning: LoadPackage can't find package /BEURRE_040824_041224/NewMaterialParameterCollection. [2024.04.29-16.49.46:563][970]LogUObjectGlobals: Warning ...
[CrashReport] UE4Editor_Engine!FBlueprintDebugData::FindBreakpointInjectionSites() [blueprintgeneratedclass.h:382]
UE - Gameplay - Blueprint - Aug 29, 2017This is a common and longstanding crash that has occurred since at least 4.9 and affected over 280 users. User DescriptionsI added an item to a BP struct. Last time I did this (several months ago) ...
Fracture Mode > "Remove-On-Break" setting: Cluster Crumbling causes flickering
UE - Simulation - Physics - Destruction - May 10, 2025Fracture Mode > "Remove-On-Break" setting: Cluster Crumbling causes flickering. Once the Remove-On-Break Cluster Crumbling effect is activated, there is a small delay between the disappearance of th ...