I do have exact same issue you described, works fine when creating new item and adding elements in the array, but if attempt to edit such item and remove or add elements I get exact same error. Did you find a solution?

Hi, I had a similar issue with my iPhone and Xcode, even when the phone was connected to the Mac via USB cable still had issues. For me what worked was to close the VPN client. Once the VPN client is closed, I could debug over USB without problem. Another colleague had even worst issues where the Xcode did not recognise his phone even has been trusted. After trying to unpair the phone he couldn't pair it again anymore. Killing usbmuxd seems to do nothing for that problem. For him, remove all Xcode cached directories and rebooting the system seemed to get it somehow. But then started experiencing extreme slowness while debugging. Even on my personal computer where I don't use VPN had some glitches and issues while trying to get all to work. As always Apple did a terrible testing job when releasing new OS and tools, I can't understand how they keep repeating the same mistakes year after year. So as a short summary: Ensure you don't have a VPN connection active while debugging neither on the iOS or Mac If still having issues with it, clean DerivatedData and reboot the Mac. Those steps seemed to work fine for me and my colleague. I hope this helps you too.