Unity Hard Crashes When Editing Behavior Graphs

Fire Chicken 7 months ago in Behavior updated by Marti (Lead Developer) 2 months ago 7

Unity shuts down when creating simple behavior graphs in a new project/scene. Unfortunately I don't have concrete steps to reproduce this issue, but it happens fairly quickly (after a minute or two) on Unity 2019.3 and 2020.1. The crash happens on 2018.4, but it takes longer... after ~15 minutes. I'm developing on a Macbook running Mojave (if that makes a difference).

Unity version:
2018.4, 2019.3, 2020.1
Game Creator version:

It seems like this is happening because the subInstances argument for UpdateSubEditors, in Assets/Plugins/GameCreator/Core/Editor/Extensions/MultiSubEditor.cs, is sometimes null. The method uses the argument without checking if it is set. Exiting the method at the beginning (if the argument is null) stops Unity from crashing.

Under review

Hi Hot Wing. If this happens again, would you mind attaching the whole error log? That way we can narrow down where the problem is.

Yes, I'll do that. When it happens I'll take a screenshot of the behavior tree as well... maybe that will yield a clue.

I’m having the same issue with same specs (Unity 2019, MacBook Mojave)


The latest Unity version seems to have fixed the asset pipeline. Could you try downloading Unity 2019.4.3f LTS? Important to note the 3f version.


Same issue here with 2019.4.0f1 LTS. Dowloading and setting the 2019.4.4f1 LTS in project resolves the issue.


Yeah I'm closing this thread. The latest version (2019.4.3f and up) do seem to solve the problem. If anyone experiences any issues after updating, feel free to reopen this.