Description

Timeline tracks can be given the same name as existing execution inputs, which causes some unusual behavior when dragging off the pin. Renaming them will rename the execution pin instead, and compiling thereafter will crash the editor.

User video link:
[Link Removed]

Crash Report:
[Link Removed]

<unknown module>! UE4Editor_Core!FOutputDeviceWindowsError::Serialize() 
<unknown module>! UE4Editor_Core!FOutputDevice::Logf__VA() 
<unknown module>! UE4Editor_Core!FDebug::AssertFailed() 
<unknown module>! UE4Editor_BlueprintGraph!UK2Node_Timeline::GetPlayPin() 
<unknown module>! UE4Editor_KismetCompiler!FKismetCompilerContext::ExpandTimelineNodes() 
<unknown module>! UE4Editor_KismetCompiler!FKismetCompilerContext::ExpansionStep() 
<unknown module>! UE4Editor_KismetCompiler!FKismetCompilerContext::CreateAndProcessUbergraph() 
<unknown module>! UE4Editor_KismetCompiler!FKismetCompilerContext::CreateFunctionList() 
<unknown module>! UE4Editor_KismetCompiler!FKismetCompilerContext::Compile() 
<unknown module>! UE4Editor_KismetCompiler!FKismet2CompilerModule::CompileBlueprintInner() 
<unknown module>! UE4Editor_KismetCompiler!FKismet2CompilerModule::CompileBlueprint() 
<unknown module>! UE4Editor_UnrealEd!FKismetEditorUtilities::CompileBlueprint() 
<unknown module>! UE4Editor_Kismet!FBlueprintEditor::Compile() 
<unknown module>! UE4Editor_Kismet!TBaseSPMethodDelegateInstance<0,FBlueprintEditor,0,TTypeWrapper<void> __cdecl(void) 
<unknown module>! UE4Editor_Kismet!TBaseSPMethodDelegateInstance<0,FBlueprintEditor,0,void __cdecl(void) 
<unknown module>! UE4Editor_Slate!FUICommandList::ExecuteAction() 
<unknown module>! UE4Editor_Slate!SToolBarButtonBlock::OnClicked() 
<unknown module>! UE4Editor_Slate!TMemberFunctionCaller<SToolBarButtonBlock,FReply (__cdecl SToolBarButtonBlock::*) 
<unknown module>! UE4Editor_Slate!TTupleImpl<TIntegerSequence<> >::ApplyAfter_ExplicitReturnType<FReply,TMemberFunctionCaller<SToolBarButtonBlock,FReply (__cdecl SToolBarButtonBlock::*) 
<unknown module>! UE4Editor_Slate!TBaseSPMethodDelegateInstance<0,SToolBarButtonBlock,0,FReply __cdecl(void) 
<unknown module>! UE4Editor_Slate!TBaseDelegate<FReply>::Execute() 
<unknown module>! UE4Editor_Slate!SButton::OnMouseButtonUp() 
<unknown module>! UE4Editor_Slate!<lambda_de96dc3471181973108233c6db1f9843>::operator() 
<unknown module>! UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_de96dc3471181973108233c6db1f9843> >() 
<unknown module>! UE4Editor_Slate!FSlateApplication::ProcessMouseButtonUpEvent() 
<unknown module>! UE4Editor_Slate!FSlateApplication::OnMouseUp() 
<unknown module>! UE4Editor_Core!FWindowsApplication::ProcessDeferredMessage() 
<unknown module>! UE4Editor_Core!FWindowsApplication::DeferMessage() 
<unknown module>! UE4Editor_Core!FWindowsApplication::ProcessMessage() 
<unknown module>! UE4Editor_Core!FWindowsApplication::AppWndProc() 
<unknown module>! UE4Editor_Core!FWindowsPlatformMisc::PumpMessages() 
<unknown module>! UE4Editor!FEngineLoop::Tick() 
<unknown module>! UE4Editor!GuardedMain() 
<unknown module>! UE4Editor!GuardedMainWrapper() 
<unknown module>! UE4Editor!WinMain() 
<unknown module>! UE4Editor!__tmainCRTStartup() 
Steps to Reproduce

1. Open any project
2. Open any Blueprint
3. Create a new Timeline
4. Create a new Function track in the Timeline
5. Name it "Play"
6. Pull off the new Play pin in the Event Graph
7. Rename the Function track "Rename"
8. Note the Timeline node has renamed the Exec input instead of the Function track
9. Compile

Results:
Pulling off the function pin when it has the same name as an Exec input will instead pull off the Exec input. Compiling after renaming the function will crash the editor.

Have Comments or More Details?

Head over to the existingAnswerHub thread and let us know what's up.

0
Login to Vote

Fixed
ComponentGameplay - Blueprint
Affects Versions4.6.14.8
Target Fix4.9
Fix Commit2572867
CreatedJan 13, 2015
ResolvedJun 1, 2015
UpdatedApr 27, 2018