[Crash] Editor CTDs when editing function parameters

I have a crash bug when editing blueprint function parameters:

  1. Create function.
  2. Open the function and create three or more new input variables (no need to edit type or name).
  3. Attempt to create an output variable.

Edit: This may be related to macros. Before step 2, adding a macro to the function (but not hooking it up) seems to dramatically increase the likelihood of a crash. For the record, I’m currently replacing some macros with functions, so I’m copying their parameter lists.

Editor will crash to desktop (CTD) with the following call stack:

FBlueprintGraphActionDetails::OnAddNewOutputClicked | blueprintdetailscustomization.cpp:L3019
TBaseSPMethodDelegateInstance_RetVal_NoParams::Execute | delegateinstancesimpl.inl:L223
TBaseDelegate_RetVal_NoParams::Execute | delegatesignatureimpl.inl:L996
SButton::OnMouseButtonUp | sbutton.cpp:L194
FSlateApplication::ProcessMouseButtonUpMessage | slateapplication.cpp:L3342
FSlateApplication::OnMouseUp | slateapplication.cpp:L3310
FWindowsApplication::ProcessDeferredMessage | windowsapplication.cpp:L885
FWindowsApplication::DeferMessage | windowsapplication.cpp:L1140
FWindowsApplication::ProcessMessage | windowsapplication.cpp:L336
FWindowsApplication::AppWndProc | windowsapplication.cpp:L274
WinPumpMessages | windowsplatformmisc.cpp:L566
FWindowsPlatformMisc::PumpMessages | windowsplatformmisc.cpp:L594
FEngineLoop::Tick | launchengineloop.cpp:L1927
GuardedMain | launch.cpp:L133
GuardedMainWrapper | launchwindows.cpp:L118
WinMain | launchwindows.cpp:L183
__tmainCRTStartup | crtexe.c:L528

Hi Luke,

I have tested in Beta 6, and I have not yet been able to reproduce this crash. Based on your information, I have tried with the following steps:

  1. Create a new Actor Blueprint
  2. In the Blueprint, create a new Function
  3. Also create a new Macro
  4. Open the Function, drag in the Macro
  5. Select the Function, add 3 new Inputs
  6. Add a new Output

At this point you suggest that you crash, but I have had no issue, even after compiling.

Is your crash occurring in a new Blueprint (like my repro steps)? Or does it only occur in a particular pre-existing blueprint? Is the Blueprint being used in the level or referenced by anything else?

Any information you can provide regarding specific repro steps or blueprint setup would be appreciated.

Thanks