@DTS Engineer Thanks, Greg. I would appreciate any assistance you can provide. I've posted four fully symbolicated crash logs for the iOS 18 simulator RealityKit crashes at https://github.com/drewolbrich/realitykit-ios-18-simulator-crash-logs I would have included them here, but Developer Forums doesn't appear to allow IPS file attachments. Please let me know if there's anything else I can do to help.

@DTS Engineer Also, I don't know if this is related, but in Xcode 16.1 beta, in the iOS 16 simulator, ARView(frame:cameraMode:automaticallyConfigureSession:) always crashes, and logs the error RealityKit/ARView+AR.swift:71: Fatal error. It no longer appears possible to use the iOS 16 simulator to test an app that uses ARView.

@real_pygod A possible workaround is to use the iOS 17 simulator, which does not appear to be affected by this issue. If testing on iOS 18 is a requirement, you can use an iPhone instead of the simulator.

@DTS Engineer I've also posted three other replies to my original post, describing other simulator-only iOS 18 RealityKit failures I noticed while acquiring the crash logs I posted above. For these failure, no crash log could be acquired.

Thank you. It's helpful to know I'm not doing anything wrong.

@cat_face11 Please mark this Apple engineer's reply as the accepted answer so it shows up at the top for other developers who find this page.

The sudo installer fix worked for me. Thank you for the detailed explanation.

See also https://developer.apple.com/forums/thread/696035?answerId=697768022#697768022 from 2021.

Thank you for responding. I've submitted FB15105272.

I wonder if there's a delay because of the impending iPhone 16 launch.

Thank you. I've responded to this reply below at https://developer.apple.com/forums/thread/762182?answerId=800569022#800569022 (developer forums has a 500 character comment limit)

After further investigation, I’ve isolated the problem to the use of ARView in a presented view controller along with a UIViewControllerAnimatedTransitioning custom dismiss animation (of the presented ARView view controller) that occurs immediately before the call to scrollToItem(at:at:animated:) in the view controller revealed when the presented ARView view controller is dismissed. Given this new information, I have resubmitted this issue as FB14718433.

I posted two possible workarounds below: https://developer.apple.com/forums/thread/761068?answerId=798573022#798573022

Thank you for responding. I've submitted this feedback: FB14615051

Thank you, this is extremely helpful to know. I had incorrectly assumed that Previews used RealityKit.