Screen image of my app

The link below is archived crash logs.

There are eight crash logs in zip file. In all of them, my app crashed because of EXC_BAD_ACCESS (SIGSEGV) in com.apple.scenekit.scnview-renderer thread.

In my investigation, main thread is processing SKNode childNodeWithName in 6 cases of 8, and SKNode removeAllChildren in 2 cases of 8 when crashed. I guess there are some race condition or something between these SKNode function and SCNView renderer.