🥳 Solution: I resolved this by deleting ~/Lbrary/Preferences/com.apple.keychainaccess.plist 🧂Saltiness: I'm a long time Apple fan and developer. Apple is really pushing it recently with its endless of horrendous (developer) software updates. It's really getting on my nerves. Just wanted to say that. ✝️ R.I.P. Steve

Can confirm that this is definitely an issue. It is happening on both my work and personal Mac's. In true Xcode fashion it is also happening to one of my colleagues, but not the other. Xcode works locally with the simulator, but for devices it gives the following error: Failed to prepare device for development. Domain: com.apple.dtdevicekit Code: 806 Recovery Suggestion: If you are certain that Xcode supports development on this device, try disconnecting and reconnecting the device. User Info: {     AssociatedMobileDeviceFunction = AMDeviceMountImage;     DVTRadarComponentKey = 487927;     NSLocalizedFailure = "This operation can fail if the version of the OS on the device is newer than the version of Xcode that is running."; } I appreciate @Eskimo's thorough answer, but I think I share @Iksmode sentiment that Apple should be frantically fixing this. There really are a lot of reports about this bug if you google. For instance: https://github.com/iGhibli/iOS-DeviceSupport/issues/151 Thanks

Solution: Switching the Xcode simulator GPU fixed it for me Simulator File GPU Selection Prefer Discrete GPU RIP Steve.