I’ve come across a bug - I’m not sure how it originated. I am able to reproduce it, but not sure if it is something specific to my project or the Behavior Tree in general.
**Issue: ** While working on Behavior Tree AI scripting, I went to compile a Behavior Task. The editor crashed to desktop, without crash report. The problem started when I attempted to rename a Custom Event. The editor then crashed every time I attempted to compile any Blueprint from that point on. As near as I can tell, it’s possible a ‘stat may be assigned to two groups’, but I’m not sure that is the problem. I’ve attached logs and managed to get a crash report, both of which are attached.
I’ve managed to trace this down to my Behavior Tree asset. I took the following steps and have been able to compile, but the crash still occurs:
Created another new Blueprint project and migrated all assets to it. Crash reproduced.
Created another new C++ project and migrated all assets. Crash reproduced
Created another new C++ project and bit by bit migrated assets. At this point I was able to compile without the crash, until I migrated the Behavior Tree. Crash reproduced.
Created another new c++ project and bit by bit migrated all assets, except for all Behavior Tree related assets, which at that point I re-created them from scratch. Upon creating the Behavior Tree, the compile action crashed the editor.
I discovered that if I renamed the Behavior Tree asset by adding ‘.BAD’ after .uasset, opened the editor, I was able to compile Blueprints.
With the editor still open, I renamed the Behavior Tree asset back to a correct name, I was able to compile.
I reset the ‘RunBehaviorTree’ in the Controller blueprint, and was able to compile.
Then I close the editor, then restart the editor, and compile crashes the editor.
I repeat the steps taken above and am able to compile.
I am using Github source 4.4. This issue now happens 100% of the time. I’m having trouble with the attachment function here, so the attachment may be in an edited post. It keeps telling me the file type is invalid. Please let me know if you need more info or additional assets.
Thanks,
Edit - I can’t seem to attach anything to this post with the file type invalid error. I’m putting the log text below. If you need the dump file or the asset, I’ll have to email themlink text - I managed to upload in .zip file. link text
Hello,
I logged this issue to our database but I wasn’t able to reproduce it on the latest Engine code. I created a new Behavior Tree with a Behavior Task in it. Then I played with Behavior Task blueprint by adding some simple logic there and using Custom Events. I tried renaming Custom Events and after it I compiled Behavior Task blueprint. I didn’t experience a crash at all.
Can you attach your Behavior Task blueprint to the thread, maybe this will help me to reproduce this crash on my machine.
I’ll upload all the Behavior Tree and related assets when I get back to my PC later on. I do have an update on this issue:
I renamed one of the referenced Behavior Tasks as part of refactoring and the crashes stopped and I haven’t been able to reproduce the error. I do have a backup of the crashing assets. I’ll verify that those assets still crash and I’ll upload those assets and hopefully there may be something in those that can help you track this down. I’ll also upload the ones that seem to work as well, maybe you can diff them and see where the issue lies.
Here are the uasset files - the editor crash is reproduce-able with the file in the behavior_crash.zip. Also attached are the renamed files in the behavior_good.zip. I have made changes since, so the files won’t be exactly the same at this point, but the issue is no longer there since i re-named BTT_MoveToCharacterTarget to BTT_MoveAndAttack. Thanks for checking this out.link text
Here are the uasset files - the editor crash is reproduce-able with the file in the behavior_crash.zip. Also attached are the renamed files in the behavior_good.zip. I have made changes since, so the files won’t be exactly the same at this point, but the issue is no longer there since i re-named BTT_MoveToCharacterTarget to BTT_MoveAndAttack. Thanks for checking this out.link text
EDIT: lol - for some reason the upload function is acting weird - both files are in an above post!
