Xcode 12: Failed to start remote service "com.apple.debugserver" on iOS device

I was able to fix the Xcode 12 app install/deployment issue described above:

Failed to start remote service "com.apple.debugserver" on device.

Domain: com.apple.dtdevicekit  
Code: 811
Recovery Suggestion: Please check your connection to your device. 
User Info: {  
  DVTRadarComponentKey = 261622;  
}
...

by doing the following steps:

1. Quiting Xcode.
2. Deleting Xcode cache directory (ie, rm -rf ~/Library/Caches/com.apple.dt.Xcode).
3. Rebooting the offending iOS device.
4. Connecting the iOS device to Xcode by cable (instead of wireless network connection).
5. Starting Xcode again.

By the way, I've a setup very close to yours:

• Xcode 12.5 (build 12E262) and
• iOS 14.5.1 (on a iPhone Xʀ device)

I fixed this by:

• Close Xcode

Deleting the current iOS version in my folder that's related to my device.

~/Library/Developer/Xcode/iOS DeviceSupport

Restart Xcode and wait a little bit for it to refresh and copy cache files in my case then Run.

Based on this article in Stack it's ok to delete the iOS supported version. Can I delete from the iOS DeviceSupport?

I noticed when I did it and reconnected my device it re-downloaded the iOS device Support files. If the support files don't download and the cache files are not copying, try restarting your computer as well.

I started also getting this error:

Errors were encountered while preparing your device for development. Please check the Devices and Simulators Window.

Restart your phone and reconnect it to the compter if this happens. Then you should get a message in Xcode saying:

Preparing your phone for development.

/----------------2nd solution-------------/

1. Unpair the device in Xcode.
2. Clean the project.
3. Unplug and then restart iPhone.
4. Restart Xcode.

/-------------Update---------------------/

None of the above worked but I was able to run the program be re enabling

Connect via Network

After doing this now I can run project via USB... I have submitted this bug to Apple.

/-----------Result from bug report--------------------/

Apple also suggests this can be caused by faulty data cords. Maybe try another cord as well. /-----------------------------------------/

Unplug the iPhone, Turn it off and again turn it on and reconnect. It worked for me. Sometimes iPhone Debug connection network server clogs up. When you restart iPhone it reinitiate the connection.

This may not be relevant for others since I've seen the issue be solved by the most random things for different people, but what ultimately did it for me was uninstalling a profile I had by going to iOS Settings > Profile > Remove

I had to update Xcode to fix this issue because my version of Xcode did not support my up-to-date iOS version.

I have the same problem, my solution is update my ios version(15.1 to 15.2 beta)

I tried all the resolvent, nothing worked

• restart iOS, Xcode, macOS
• clear DeviceSupport, Caches
• unpair iphone, change lighting cable

Then I find my ios version(15.1) does not exist in /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport.

I try to fix it, but failed.

Finally, I can only update my iOS device to 15.2 beta version, It solved! Xcode is update to beta version too.

My devices original version:

• iOS 15.1
• Xcode 13.1 (13A1030d)

I reset the iPhone network settings and it works!

I've had the same issue and also had the problem that I wasn't able to connect my device by cable (it popped on and of), so I had to use wifi connection on Xcode.

I was able to see the icon of the app created by Xcode on my iOS device, but whenever I tried to start it, it won't do so giving the "Untrusted Developer" error message.

I fixed this by going to: Settings > General > VPN & Device Management > Developer App

Here you have to chose the App and consent to trusting it.

I'm on Xcode 13.3 and I fixed this by unplugging and plugging the cable between my MacBook Air and my mini iPad 3.

I fixed it by, Following the steps : Window > Device and Simulator > Select your device and Right Click on it > Unpair after that re-connect your iOS Device then boom... Clean builds and run the app, it will work for you.