I had a a similar error on iPhone6S after Xcode 12.2 upgrade. _shouldMakeReadyForDevelopment I noticed it mentioned passcode, which was disabled on my iPhone6S. So I re-enabled the passcode and now I can get the app to run. Now all apps (including ones created with Xcode 12.2) take > 30secs to load when debugging on device. There is no such problem with my iPhone 6 device running iOS 12. Devices 'Connect via Network' tick/untick makes no difference.

Thanks again eskimo for the link, see Triggering the Local Network Privacy Alert - https://developer.apple.com/forums/thread/663768. We added the UDP write functions which are in Swift, and this is an Objective C app, so had to go through the motions of creating a Swift bridging header to import into ObjC - see link. - https://developer.apple.com/documentation/swift/imported_c_and_objective-c_apis/importing_swift_into_objective-c Also wrapping the function calls in a class with @objc modifiers. The Network Permissions request [i] now pops up immediately which is a big improvement. It still takes about a minute for the UDP to start being received after that, provided you unload and re-open the app. But it seems to start reliably enough now. Side note: I get a device black screen when running the app in debug mode on iOS 14.2 with Xcode 12.2 RC. [i] Here's the exact text of the pop-up to maybe help people find this post: App Name would like to find and connect to devices on your local network. This app will be able to discover and connect to devices on the networks you use.

Good suggestion eskimo , just updated from iOS 14.1 to iOS 14.2 (on iPhone 6S) and still no UDP reception. (Warning , you also need a 10GB download of Xcode 12.2 RC to deploy to iOS 14.2 ) We tried uninstalling and re-installing via TestFlight - still nothing. We left it for a few hours, then opened the app again and were prompted with a pop up : "xxxxx would like to find/connect to local devices on your network" We clicked OK and now it does receive the UDP packets. So - the question is should it have displayed that pop up earlier and if so how can we make it appear on first install ? One Stackoverflow - https://stackoverflow.com/questions/63525026/what-triggers-the-would-like-to-find-and-connect-to-devices-on-your-local-netwo says this is a Bonjour request, but this app does not use Bonjour. So should I add this entitlement to ensure the pop up appears sooner ? Another Stackoverflow post - https://stackoverflow.com/questions/64308595/how-to-trigger-the-local-network-dialog-authorization-for-multicast-entitlement suggests to move minimum build target to 12.0 which is what we have, so maybe we should increment this more ? Any more suggestions welcome.