Corrupt Behavior Tree: Sequence replaced with Node_Composite?

Not a question as much as a bug report with Behavior Trees:

Today when I reopened my behavior tree that I’d been working on, I noticed a sequence node (that had previously been set to observer aborts: none) had been replaced with a node labeled “BehaviorTreeGraphNode_Composite”. This new node had Observer Abort Authority set to ‘self’, which (when clicked on) caused the ENTIRE graph to be highlighted including the ROOT node (suggesting its failure aborted the entire tree?). My AI subsequently did not do anything anytime it hit that node.

  • I’m using a subclass of AIcontroller and a pawn subclass of Character
  • This is Content/Blueprint only–no source code shenanigans here
  • All files had been working the previous night–even after an editor restart…so everything was saved up
  • I HAD click-dragged a decorator from one node to this one at some point the previous day (a handy feature, though perhaps that’s where this bug begins…?)
  • Upon dragging that decorator over to a different node, and then back to this weird node, the observer abort highlighting changed from highlighting the entire graph to just the node shown in the attached image…which is still incorrect if my understanding of ‘self’ is correct (it should just be the “gettargetLoc” task node that gets highlighted…right?)
  • The VERY last thing I did before I shut down the editor last night was actually change that particular node’s observer report to ‘self’ and ‘lower’ so I could show off the tree highlighting feature to my wife, who was curious about the tech. She actually watched me change it back to none before I saved/quit though.

Anyway, hopefully this helps you track down and resolve the issue. Deleting that node and rebuilding that section of the tree seems to have restored functionality…I’ll chime back in again if another editor restart corrupts the tree again.

Hi - thanks for the report!

What version of the engine did you encounter this issue with?

I’ll try to get a reproducible case for this issue - the drag/drop does indeed sound like a suspicious candidate!

Huh, I had been sure this was in 4.3.1, but I just checked and it looks like it was 4.2.1. I can migrate the project and see if the problem reappears. If it WAS the drag and drop, then a repro steps would be to drag the same decorator around multiple times, to multiple nodes (since that was what I was doing), and then save/quit/reopen.

I’ve tested this locally in our Main branch (post-4.4) and cant reproduce it so far.

If you can come up with a consistent set of steps that would be awesome. Would it be OK if I closed out this post until then?