Split structure pins on Array Add and Array Insert are disconnected on project startup

Version 4.4.2


  1. Set up and array of a splitable structure type. It can be built in like vector or custom.
  2. Add an item to the array via Add or Insert using a split pin.
  3. Save. Compile. Play.
  4. Close the editor and reopen the project.
  5. Open the blueprint and there is a warning on on the add/insert node and the pins have been disconnected and recombined.


Subsequent project loads:

Further investigation on this has led to to suspect
UK2Node_CallArrayFunction::PropagateArrayTypeInfo in as the likely culprit here. I believe this is the only function in the execution path that could cause this.

My gut tells me that it is checking the array type and seeing that the split struct pins do not match that type and and is disconnecting them.

The Blueprint schema and compiler is pretty complicated so I can’t really say for sure without testing. As this is easy enough to work around with a break+make node I’ll leave that to the good people at Epic.

Hey .

I can’t replicate your issue in 4.4.3. Specifically, I can’t create an extended Add node like you have in your first picture. I believe that that workflow for working with structs is deprecated and that using break/make nodes are preferred, but I can continue to investigate the issue if you’d like.



Seems like 4.4.2 was this end of this if we can no longer split pins on arbitrary nodes. I was just reporting it because I came across it while using the format for convenience in testing something. It does have some visual appeal even if its not the most logical representation.