4.3 to 4.4 Behavior Tree is empty but working

Development Programming & Scripting AI
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1

Hey, i just ported my Game from 4.3 to 4.4 and my Behavior Tree is empty all of a sudden. But if i start game, tree is working.
Even values are updating in lower right corner.

Did i miss something?

http://puu.sh/aVy1Y/c7ea0539eb.png

Info Failed to load /Script/BehaviorTreeEditor.BehaviorTreeGraph Referenced by NPC_Villager_Tree Property /Script/Engine.Blueprint:EditedDocumentInfo.EditedObject
Info Failed to load /Game/Blueprints/NPC/Villager/BP_NPC_Villager.BP_NPC_Villager_C Referenced by EdGraphPin_47118 Property /Script/Engine.EdGraphPin:DefaultObject
Error /Game/Blueprints/NPC/Villager/BTS_ChangeTasks : Can't find file for asset. /Script/BehaviorTreeEditor
Info Failed to load /Game/Blueprints/NPC/Villager/BP_NPC_Villager.BP_NPC_Villager_C Referenced by ObjectProperty_372 Property /Script/Engine.Pawn:AIControllerClass
Error /Game/Blueprints/NPC/Villager/NPC_Villager_Tree : Can't find file for asset. /Script/BehaviorTreeEditor
Info Failed to load /Script/BehaviorTreeEditor.BehaviorTreeGraph Referenced by NPC_Villager_Tree Property /Script/AIModule.BehaviorTree:BTGraph

These are Log Lines when i start editor. Where does this come from? And yes, i only updated game from 4.3 to 4.4.

I could go on and use 4.3 though…

2

Hello. eXi! I fall into same problem. And i think i found some hint…
So, when my game was on 4.3, config file DefaultEditorUserSettings.ini contains “bBehaviorTreeEditor=True” line. After upgrading my project to 4.4 everything was ok, but when i open EditorPreferences/Experimental, change smthng and press SetAsDefault this line automaticaly deleted from config (because behavior trees not experimental any more). Without this line i got problem that you describe earlier.

3

So i need this line to not have problem? But my when i upgrade my game, behaviour tree is directly empty. I didnt change anything, just opened 4.4 version.
I dont even have a DefaultEditorUserSettings.ini in 4.3 version. Only a EditorUserSettings.ini.

There is following line:

[/Script/UnrealEd.EditorExperimentalSettings]
bBehaviorTreeEditor=True

If i now upgrade project, error directly comes up and its only a specific Tree. I got a second tree that is running fine.):

4

Ok, i got it fixed, but still after upgrading my tree was empty.

I changed something in my Editor Preferences (like turning on UMG) and deleted broken Tree.
Than i restarted editor and copied Tree from 4.3 version into same folder of my 4.4 version. Now it’s visible.

Don’t know what causes this error.

5

Experiencing this as well, answer didn’t solve it.

In my case only time I get this error is when I try to reference Behavior Tree inside C++. Commenting out reference stops error from appearing.

6

I’m getting this problem right now. My behavior tree is huge and I wouldn’t want to be redoing this. Have you guys managed to found a solution to this other than rebuilding behavior tree?

7

Like i said in my answer:

Try copying Tree File from your 4.3 Project over to your 4.4 one.

8

I’ve already upgraded to 4.4 few weeks ago and had a tonne of changes.

editor tree now works. But tree remains empty. :frowning:
There are a lot of chnages and re-creating it would make me very sad.

9

Didnt you upgrated to 4.4 by creating a copy? It’s not good overwriting 4.3 project with 4.4 because if your project breaks you can’t work on with 4.3 version.

10

nope. did not create a copy. Anyway at worse we do have SVN . but it’s been almost a week since I commit to change.

So it’ll be sad if i can’t recover it

Anyway that issue aside. AI is working perfectly well. I’m fairly sure data is still working in there, it’s just that nodes are not appearing.

11

Yes i know. I have same problem. But still, in future, never overwrite when upgrading. Always click on copy button.
I don’t know how to fix this without working tree file from old project.

12

I think I should add that I had this happen to a tree that I only created in 4.4, it didn’t exist prior to switching to 4.4.

13

Ok than Staff team should get on this case.

14

Hey eXi,

We’re not sure what caused this, but I’m glad you got around issue. Without a reproducible case, though, we may not be able to figure out what happened. Would you mind zipping and attaching 4.3 version of .uasset file for behavior tree with which this happened? If possible, I’d like to run through it some here. Thanks!

15

file is working at moment. I haven’t changed it, so i will still upload it.
If it breaks again, i will upload broken version too.
Meanwhile you could ask other guys on Question to share their project files, because they ran into similar problems with new 4.4 Projects.

16

Okay, I wasn’t able to reproduce problem with that file. If anyone else experiences this issue, please let us know if you’d be willing to provide us with 4.3 version of project and we will try to reproduce it here. Without that, we aren’t able to see what caused problem in first place. Thanks!

17

Is there any hotfix for this issue? I’m stuck with one behavior tree being empty every time I restart my project. I’m waiting for 4.5 to hopefully have a fix but is there anything I could do to fix this issue right away? I heard 4.5 won’t be released for a while and I’m not even sure if it fixes this issue or not :confused: . Anyone have any info?

18

Hey pzea,

As I mentioned in your other post, there isn’t a hotfix for this issue and we’re still not sure how it happens because we’ve been unable to reproduce it internally.

Did this issue occur after converting your project from 4.3 to 4.4, or did it begin in 4.4? Would you mind zipping and attaching .uasset file for behavior tree with which this happens? Thanks!

19

Hey pzea,

We haven’t heard back from you, so I am marking this post as resolved for tracking purposes. If you are able to provide details and assets requested above, we will reopen investigation. Thanks!

20

Hi, thank you for response. So I downloaded 4.5 preview but unfortunately problem is still there. My Behavior Tree is still empty. I made a new one and copied same functionality until it worked. Then when I restarted engine Behavior Tree was empty again. It’s frustrating :/. BT works, but it’s empty when I look at it.

Here is Behavior Tree from 4.5 preview version of my project.