If you don't know/understand what "We were still unable to review your app as it crashed on launch.", for some reason, why not just say "I don't understand what We were still unable to review your app as it crashed on launch means". If you do understand what it means, they why post it with no further details? I just don't get it, how can you possible be hoping for any help from this forum with this?

Why? I mean just why would you post something like this? You and the hundreds of others that do similar. Is this a question you've posted, no it is not. Is this a request for assistance/help/comment you have posted, no it is not. Is there any useful information you have attached or added, no there is absolutely nothing at all. Do you really think you will get some feedback on this? What will posting quote from Apple review achieve. Nothing. Nothing at all. Good luck

Installing the app has become worse. It'll be fine one minutes, will install and run quickly, and then next go it'll take about 10 minutes. It knows its taking a long because it says its taking longer than usual and do you want to proceed? If you say yes, you still have 10 or more minutes to wait. Once its started doing this I've not found any way of making it right again other than to restart the Mac and the phone. The problem is, whenever you restart a phone, then you then have to wait 5 minutes while Xcode says "Preparing the iPhone", even if its already prepared it a trillion times before. So you can't win.

Same here

Have you first just tried to create a new simple React Native app to check your Macbook is configured corrected to create/build/run any RN app

Not a crash, but with a React Native app it hangs at random places when downloaded from TestFlight, yet the exact same build when installed from the App Store is ok (the app was uploaded to TestFlight, then released to the App Store, then later found the issue in TF). So the exact same build experiences issues when installed from TF but not when installed from the App Store.

(Connecting via USB to the iPhone)

Upgrade to iOS 17.3

There's no way at all. You can neither obtain the phone number of an incoming call nor retrieve the last caller(s) numbers from the device itself.

I'm going to have to raise an official Apple support ticket, my MacBooks been out of action all day long because of this.

Thanks @BornP for answering and making some suggestions, more than any of the Apple folks have done. Unfortunately none of these do anything to rectify the issue. Once again I'm unable to do anything, things were going fine one minute, then the next Xcode threw one of these episodes. I have 6 iPhones and its stopped working with all of them, that was several hours ago and since then just cannot install/run the app at all (same app as was working just before, no changed made). I also have 3 Macs and have observed this on all 3 of them. The one thing they all have in common is they all have Xcode 15 on them. None of these issues started until I started using Xcode 15 beta, its been present in every Xcode 15 beta and every Xcode 15 release version, including 15.2.

My (company supplied) MacBook has lots of software on it for data security type things i.e. like detecting the browsers are not connecting to malicious web sites etc. One of them is called Forecepoint, I've long suspected it of causing lots of hassles with internet usage. Could software of this type interfere with Xcode/the virtual network when an iPhone is connected via USB causing connection and slowness issues? @eskimo

I've not noticed them living longer than 30 seconds. How are you confirming that? If you have the Xcode debugger attached that might affect the lifetime

No. But why would you want to do this? The app itself is capable of detecting the iOS version

I don't know the answer, but I once tried posting a notification from a background asset extension which didn't work. However all the extensions seem a bit different in what they can/cannot do. Why don't you just try it and see what happens, should only take a few minutes coding.