Garbage collector error with blueprint hierarchies

Build Type: Binary
Build Version: 4.11.1-2934540

We have blueprints that have other blueprints as child actor component inside of them. Some of these form hierarchies at least to the 4th level. After converting project to 4.11 making changes these blueprints inside these hierarchies cause Illegal call to StaticFindObject() while collecting garbage! - error and crashes the project. Most of these blueprints contain couple meshes or sprites and some functionalities for them.

BPANDREW posted this issue to blueprint question section, here is the orginal post: https://answers.unrealengine.com/questions/402744/garbage-collection-bug-411.html

Repro steps:

  1. Created clean project.
  2. Added blueprints: MainActor, ChildActor1, ChildActor2, ChildActor3.
  3. Added CA1 as child component of MainActor.
  4. Added CA2 as child component CA1.
  5. Added CA3 as child component CA2.
  6. Then drop the MainActor to the game level.
  7. Add cube mesh to MainActor and after that sphere mesh to CA1 → Illegal call to StaticFindObject() while collecting garbage!

After this you can restart the project and everything seems fine for while, until you do again some changes in one of the blueprints or add meshes and in some point it will crash in while making the change, compiling or running the game in editor.

I am running into same problem. Kind of a show stopper. I can’t figure out where its coming from because the project is fairly developed at this point.

Hello,
I have tested that method several times, but I as well failed reproduce error just now, which is weird.

To make it throw that error, just now, I had to add and remove meshes in hierarchy then just add more back or just move the meshes and the child actor component in the local spaces randomly with the arrows. It should crash immediately or when compiling.

I had at least one mesh in every blueprint and then added couple more and moved one child actor in CA1 and then mesh in CA2.

Thanks for checking this issue.

Hello,

I have followed the above steps in a clean project, but I’m not seeing the same error on my end. When are you seeing this error message appear?

Logs

MachineId:F440E81045D3507D237D68827723F0A5

  • Could you provide the logs from your project’s Saved->Logs folder after the crash occurs?
  • Could you please cause the crash again and provide your Machine ID from the Crash Reporter window and ensure to hit send on the report?

Thank you for providing this additional information. Could you please provide a test project where this crash is occurring so that we can enter a report for it? If you have one, you can zip it up, upload it to dropbox, and then provide a link to the project via PM: https://forums.unrealengine.com/member.php?160394-Sean-Flint

I’m also having this error. Using 4.11.2 and it randomly occurs when I attempt to PIE.

I sent pm message with video showing the steps.

As far as the project’s that you’ve provided, could you please provide the steps that I’ll need to take to reproduce the error?

Hello SVR33,

Could you cause the crash to occur again and provide your Machine ID from the Crash Reporter window and ensure that you send the report?

Sean, have you been able to recreate the error? Is this problem being addressed? Thank you.

I don’t want to jinx it, but it hasn’t hit me once since I posted here. /fingers crossed. If it does, I’ll post relevant info. Thanks.

Hello mxnko,

I’m currently investigating this issue, and I will provide more information as soon as it is available.

Hello everyone,

Please test your projects using the 4.12 preview. There is a similar issue that was reported fixed for 4.12, but I haven’t been able to determine if it is the same as what you are all experiencing.

Let me know the results, and I will continue testing in the meantime.

Thank you

I tried with three projects, one converted to 4.12 preview and other created clean with code and third without. All projects crash with same steps and same way but this time with: Access violation - code c0000005 (first/second chance not available)

Could you provide the logs from the 4.12 project? That error message seems different than the one that you were getting in 4.11.

Could you also send that 4.12 crash report so that I can check it in our database?

Here the whole project with logs.

Hello,

I have been able to reproduce your crash, and have entered a bug report (UE-30242). Thank you for your report.

Have a great day

Sean do you know if its going to be addressed in 4.11.x or 4.12? Thank you!