Unreal Engine Issues
Unreal Engine Issues
[CrashReport] UE4Editor_UMG!TBaseDelegate<FMargin>::operator=() [delegatesignatureimpl.inl:381]
UE - Editor - UI Systems - Aug 29, 2017This is a longstanding and common UMG crash that has affected more than 200 users since at least the 4.15 release. User DescriptionsI was working in the UI and undid several last changes in quick s ...
Saving Behavior Tree with Blueprint task inheriting from native class invalidates Blackboard key when BP contains a function
UE - AI - Jul 8, 2025A regression introduced in UE 5.6 causes Blackboard key selectors in Blueprint tasks to become invalid when the Blueprint inherits from a native subclass of UBTTask_MoveTo (or UBTTask_BlackboardBase ...
Wrong calculation of "MaxAllocatedCountEstimate" inside FNiagaraRendererRibbons::GenerateDynamicData()
UE - Niagara - Mar 20, 2026Starting with UE 5.4, function FNiagaraRendererRibbons::GenerateDynamicData() from file [NiagaraRendererRibbons.cpp] attempts to calculate DynamicData->MaxAllocatedCountEstimate as such: DynamicDat ...
Physics simulation shows strange behavior with specific skeletal mesh configurations
UE - Simulation - Physics - Mar 3, 2017PhAT is inconsistent on when it does and doesn't apply scale to Constraint positions. This leads to cases where the positions provided create constraints that may not work when the Preview Skeletal ...
[CrashReport] Assertion failed: GetOuter()==NULL in UE4Editor_Core!FText::IsEmpty
Tools - Apr 17, 2017This is a top 10 crash affecting many users. It is believed it may be related to the auto listen / reimport feature. The callstack shares similarities to past tickets, such as:[Link Removed][Link R ...
[CrashReport] UE4Editor_PropertyEditor!SPropertyEditorAsset::GetObjectPropertyClass() [spropertyeditorasset.cpp:966]
Tools - Nov 23, 2016This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Error message: Assertion failed: Class != NULL [Link Removed] [Line: 965] Source Context: 95 ...
[CrashReport] UE4Editor_Slate!FSlateApplication::RoutePointerMoveEvent() [slateapplication.cpp:5195]
UE - Editor - UI Systems - Slate - Jun 28, 2017This is a longstanding crash that occurs with low frequency, but has affected over 200 users. One user describes that this occurred while packaging a project, although other users have not provided ...
[CrashReport] Assertion failed: !PinRef->bWasTrashed - UEdGraphPin::SerializePin()
UE - Gameplay - Blueprint - Sep 8, 2017This is a common and longstanding crash that has affected more than 200 users since at least 4.15. This crashGroup was previously associated with [Link Removed], but that specific repro case has be ...
[CrashReport] FBlueprintEditor::OnRemoveExecutionPin()
UE - Gameplay - Blueprint Editor - Jul 14, 2017This is a common crash affecting users on Mac and Windows. User Descriptionsremoving empty execution pins from sequence node Source Context 3952 void FBlueprintEditor::OnRemoveExecution ...
Functional Test won't start when placing a moving actor inside the level if setting Navigation Mesh's Runtime Generation to Dynamic
UE - Automation Test - Mar 21, 2019User is trying to use the Functional Test class to construct some automated test cases. Whilst doing this they noticed that adding a BP_Actor (just a static mesh engine cube) that simply rotates (v ...