The tunnel connection failed while the system tried to connect to the device.

Hello,

I’m new to macOS after many years on iPhone, and I’m trying to run a simple app on my iPhone directly from Xcode. The app builds fine in the simulator, but deploying to a real device fails with this error:

The tunnel connection failed while the system tried to connect to the device.
Domain: com.apple.dt.CoreDeviceError
Code: 4
Failure Reason: The tunnel connection failed while the system tried to connect to the device.
User Info: {
    DVTErrorCreationDateKey = "2025-10-02 16:55:53 +0000";
    "com.apple.dt.DVTCoreDevice.operationName" = connect;
}
--
The tunnel connection failed while the system tried to connect to the device.
Domain: com.apple.dt.RemotePairingError
Code: 4
--

I get the same error via command line, e.g. for

xcrun devicectl device info apps --device "..."

My setup:

  • macOS Version 26.0.1 (Build 25A362)
  • Xcode 26.0.1 (Build 17A400)
  • iPhone 13 on iOS 26.0.1
  • iPhone is paired with the Mac (I can see it in Finder and in Xcode alongside the simulator).
  • Developer Mode is enabled on the iPhone.
  • I also see my Apple Watch listed in Xcode.
  • I might have enabled Multipath networking in the past - but in iOS 26.0.1, the setting is missing in the Developer settings - so there is no way to check if it's enabled or to disable it. I know this was the solution to a similar problem: https://developer.apple.com/forums/thread/737907

What I tried:

  • Restarted both Mac and iPhone, unpaired them, paired them again.
  • Disabled and re-nabled development mode
  • Tried both Wi-Fi and wired connection (Apple-certified cable).
  • Reset privacy and network settings on the iPhone.
  • Verified I’m not running any VPN.

Despite this, deployment always fails with the same tunnel connection error.

Has anyone encountered this before or found a solution/workaround?

Thank you very much, Martin

The tunnel connection failed while the system tried to connect to the device.
 
 
Q