[4.10.1] Crash when applying instance changes to Blueprint

Hi there,

when I try to write changes to the class defaults of an Blueprint actor instance back to the blueprint, the editor crashes.


Maybe this is an issue with nested structs or something. Here’s the crash log: MachineId:E41A3D4D43CC73524EE9A8AD024CD4DFEpicAccountId:fba125fe5ed14161aba130 - Pastebin.com

Hi ,

  • Does this occur in a clean, blank project with no additional content or is it limited to one project?
  • What steps can I take to reproduce this on my end?
  • Is this limited to one type of blueprint?
  • What specific changes are you making that cause this to occur?
  • Can you post your crash logs here? They can be found at \Unreal Projects\PROJECTNAME\saved\logs. The file linked in your thread above is the crash callstack.

Ok, I’ll check this on monday and report back.

Ok, here are the [crash logs][1]

And here is how to reproduce this bug (phew, took me about an hour to hunt this down):

  • Create a new project
  • Create a struct like this (array of text seems to be the culprit here):

  • Create an actor Blueprint
  • Add a single variable for this struct, make it an array
  • Make the variable editable

  • Insert an instance of this blueprint in the level
  • Add a member to the editable variable (add a member to the text array also, this is what seems to cause the crash later)
  • Now try to save this value back to the blueprint

  • Enjoy the crash :slight_smile:

I attached you a super-simple, [ready-to-crash testproject][5], too :wink:

(Empty level with just a single BP_CrashTest)

Hi ,

Thank you for the project. I was able to reproduce this and have entered a bug report, UE-24455, to be assessed by the development staff.

Thank you.