Dealing with “Failed to prepare device for development” Error Message in Xcode
You update your iOS device to the latest version of iOS. Now you try to run your Xcode project on that device. An alert pops up in Xcode with the message Failed to prepare device for development.
Why Are You Getting This Message?
You are getting the Failed to prepare device for development message because the device is running a newer version of iOS than Xcode supports.
Each version of Xcode ships with a version of the iOS SDK. The Xcode Releases site has a list of each version of Xcode along with the iOS SDK. The version of the SDK is the latest version of iOS that version of Xcode supports. You won’t be able to run your Xcode project on a device running a newer version of iOS.
For example Xcode 13.2.1 ships with the iOS 15.2 SDK. If you are running Xcode 13.2.1, you won’t be able to run your project on a device running anything newer than iOS 15.2. If you have a device running iOS 15.4, you won’t be able to run the project on that device with Xcode 13.2.1.
How Do You Fix the Error?
The easiest solution is to install the latest version of Xcode. The latest version of Xcode has the latest version of the iOS SDK so you’ll be able to run and debug your project on a device running the latest version of iOS.
If your Mac is running an older version of macOS, you might not be able to update to the latest version of Xcode. Xcode 13.3 requires macOS 12. If your Mac is running macOS 11 and can’t run macOS 12, you won’t be able to update to Xcode 13.3. What do you do then?
There are two workarounds. The first is to download iOS support files for the newer iOS version and copy them to your Xcode app bundle.
The second workaround is to deselect the Debug executable checkbox in the Run step of the scheme. After the app launches, attach it to the debugger. The following article provides details and screenshots:
Debugging on iOS 15 with Xcode 12
iOS 17 Update
Starting with iOS 17 Apple no longer includes iOS support files so the first workaround won’t work. According to the following Stack Overflow question:
How to run on iOS 17 Device using Xcode 14
The solution is to run the following command in the Terminal and restart Xcode:
defaults write com.apple.dt.Xcode DVTEnableCoreDevice enabled
Turn off Automatic Updates on Your Device
Keeping up with the latest version of iOS requires using the latest version of Xcode. Xcode takes a long time to install. If you don’t want to be constantly updating Xcode, turn off automatic updates on your iOS device.