When I started up my project this morning, my AI have stopped moving and I get this error every time I run the game (the game still runs normally but when I stop I get this list of errors.) I don’t know what’s wrong…
I don’t think I wrote the variable name wrong or any small mistake like that.
Any ideas?
Hello,
This type of error is usually referring to an issue where a pin is returning a null value. It is possible that it could be your Get Blackboard node in your AI Character. Instead of connecting a reference to self, try connecting a Get AI Controller node, and then connect your self reference to the input pin of the Get AI Controller. See if that makes a difference.
Nothing changed, still get the error. The thing is. I don’t know why the AI doesn’t walk anymore, I didn’t change anything to do with his movement.
Wowwww, I figured it out. All I had to do was delete the Run Behavior Tree event at BeginPlay in the AI controller and then reconnect it and reset the BTAsset. I didn’t touch that before so I don’t know what went wrong with it. Thanks for the quick post
Try hooking up the execution pin (the white arrow) to the set value as bool node up top. You’ll need to get the ai controller before you set the value as a bool. This may not be the issue, just a suggestion.
Do you recall what changes you made prior to when the AI stopped working as expected?
Glad to hear you figured it out!
Have a great day
I worked only on my character and level design, not the AI at all, and now I’m getting the same error. I did what I did before to fix the error but it’s not working this time. So I also added some other stuff that I thought might help but nothing is working. I can’t tell if this is a bug or something I did wrong!
i added some new stuff to this to see if that was the problem but it wasn’t:
The thing is, this node never fires off when I start the game:
P.S. I changed the AIController name from AIController to AIButt to dismiss confusion when I would set the AI Controller Class…don’t judge the name!
Can you post a screenshot of the error you are getting this time around?
Oh yeah sorry, it’s the same error though:
When I click on the Set Value as Bool part of the error it takes me to the Set Value as Bool node on the top that is in the previous screenshot and on the next line the next error, it takes me to the other Set Value as Bool, so it doesn’t like both of them.
When are you assigning the AI character its BT and Blackboard? The error you are getting is because the AI character can’t access its Blackboard and set a Bool variable because it doesn’t have one or it hasn’t been set…Accessed None is the first part of the error take a look at the nodes that are throwing the error and see what is missing from them that should be there…click on the find node button in the error and it should pull them up.
I assign BTin AIButt which is the Ai’s controller, and Blackboard in the BT. I don’t see anything missing from the Set bool variable nodes. It’s just that AIButt never runs when the game starts for some reason and that the Blackboard never runs either (which is Wander and ChasePlayer. I think that’s the problem but I have no idea why they aren’t running
AIButt, the controller, runs BT, but this never fires when the game starts even though I set it as the Ai’s controller class:
The BT which sets Blackboard as the root:
Blackboard:
Wander blueprint that is used in the BT:
ChasePlayer blueprint that is used in the BT:
It looks like you have an empty/non-existent Blackboard…you technically have one but it looks like it isn’t setup correctly…Have you setup the key values and just closed the details panel and Blackboard panel? If not then in the blackboard click on the Window menu and select Blackboard (or make sure it has a check marked next to it) and then do the same for Blackboard Details. Now you can setup the values you want to store/set for the BT/AI to use. If you need a Bool value stored click on New Key to make a new key and set its type to Boolean name it and so on for the other values and keys you want to set. If you don’t do this the AI will never be able to set a value as Bool and you will continue to get that error message.
Also try this method to get the Blackboard:
Yes I just forgot to check the details panel and blackboard panel. I did add the self and get blackboard nodes but that didn’t work. I already had a bool value so that’s not it.
I followed these two tutorials exactly: [link text][1]
[link text][2]
and at first everything worked but the next time I loaded up the project the ai stopped moving and now I can’t fix it but nothing’s changed.
The seventh comment (Lazurus’) on the second video, the guy got the same error as me but his ai is working normally.
Blackboard with panels visible, Is Chasing bool variable is there:
I’m thinking the problem is that in the AIButt the Run Behavior Tree node connected to BeginPlay never turns on for some reason…
That was the first thing I did, I set it to some other controller and then set it back to AIButt and recompiled but no luck.
Did you change the AI controller saved in your AI to use the new “Butt” version? If it isn’t executing the begin play it isn’t using the correct controller…check your AI BP to see if the new controller is set correctly
Double check that you have the key spelled correctly and that any cases match…like if the key name is “IsSet” using “isset” to try to set the key won’t work. If you open the BT and set its debug to one of the AI in the level does it show any activity as it executes?
If you’d like me to take a look at your setup to be able to determine the issue, as it seems most of the suggestions that were offered have not resolved the issue currently, feel free to send me a link to Dropbox where I can download the zipped up project. You can PM me a link on the forums: https://forums.unrealengine.com/member.php?160394-Sean-Flint
This way I can look into your setup more closely and determine what is causing the error.
Did you ensure that you have a Nav Mesh in your level? It doesn’t look like you have one from what I can see by looking at your project.
