Editor crashes on load after editing a blueprint

Hi,

I have encountered an annoying problem whilst creating my game. I have created a heirachy of inherited blueprints that deal with pick up items, which goes pickup->weapon->specific weapon. I one of my other blueprint, in a function that is called on event begin play, I spawn a specific weapon class. This works and runs when I am in the editor, but if I close the editor and load it back up, it crashes with the error message:

!Id:a920591bc752f46bb4a668046c47deed

We apologize for the inconvenience.
Please send this crash report to help improve our software.

I can then fix this by deleting the specific weapon, which causes the spawn method (spawn actor) to reset to spawning nothing. I then change this to a different blueprint (not a subclass of weapon) and then when I put the weapon blueprint back in, the project will load again.

Coincidentally, I use the same spawn actor method on the same weapon blueprint somewhere else in my code, and that works just fine. I also just tested putting the code into a different blueprint on event begin play, but in this blueprint, the editor continues to load just fine.

I’m not sure what is causing this, any ideas,
Thanks

Thank you for your report. We have assigned this issue to a member of our support staff, and they will begin investigation as soon as possible. If we are unable to reproduce the issue, or we need additional information, our staff member will comment here with additional questions. Otherwise, we will post an ‘Answer’ once we have logged the issue in our bug database or we have a solution for it.

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Thank you.

Hi Neo_uk,

Could you provide us with your .LOG and .DMP files? Follow the bug report link posted above for directions on how to find them.

Could you also post a couple screenshots of the Blueprint in question? One of your Graph and Default settings.

Hi,

I have attached the log and dmp files, although I have had to put .txt onto the end of them because it would not allow me to upload the files as log and dmp files.

We do not want to post screenshots of our code on a public forum. Could we some how or other send them to you personally?

Also, I have just experienced the crash when I put it in the other other place that I said was working before, as in reference to this part of my original post " I also just tested putting the code into a different blueprint on event begin play, but in this blueprint, the editor continues to load just fine."

Thanks for the help

link text
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I understand. You can send them in a Private Message on the forums directly to me.

https://forums.unrealengine.com/

Hi Neo! Thanks for all the data. I’ve reproduced your issue and have some idea of what’s going on. Basically, the blueprint compiler is unhappy with the dependencies that have sprung up between your Character, Weapon, and Pickup blueprints. To be clear: there is nothing wrong with your data, the compiler simply can’t handle it at the moment.

I’m not sure if you need an immediate workaround, but here’s one anyway: removing the spawn weapon function from your character blueprint should allow you to load the data. You can, for now, spawn the weapon in your level blueprint.

Unfortunately I cannot provide a better fix immediately, the blueprints team will meet tomorrow to try and find a solution that doesn’t take too long to get out the door. I’ll get back to you with more information around noon PDT tomorrow.

We now have a likely fix, I’ll post an answer when it’s submitted. ETA is a couple hours.

The crash in question has been fixed by CL 2126365. Basically, when a blueprint had a deep (>2) class hierarchy the editor could fail to load things in the correct order.

Thanks for all your help in allowing us to track down the issue. Let me know if you have any other questions.

Good good. Looking forward to the fix.

Thanks for fixing this, when is this update likely to come available for us to use?

It’s available now in the github 4.3 branch, but I don’t recommend using that branch for development until it’s been released. The github commit in question is this one, you could pull that one commit or manually apply the change.