Xcode 26.4 refuses to pair with my Series 4 iWatch

Now it's even worse - I deleted the watch from the Xcode Devices window, thought I'd add it again, but I can't get it to show up. iPhone connected via wire, all three devices on the same WiFi network.

Thanks for the post.

If you look at the table below, Xcode 26.x minimum requirements for the Apple Watch:

https://developer.apple.com/xcode/system-requirements/

Shows the minimum is watchOS 8 and you said your Apple Watch is running watchOS 10.6.2. So no need to purchase a new Apple Watch for testing. Also the Apple Watch simulator is really good.

Pairing an Apple Watch to Xcode for development actually requires going through the iPhone it is paired with. Also enable the "Developer Mode”.

All the info taken from here: https://developer.apple.com/documentation/xcode/pairing-your-devices-with-xcode?language=objc

On the iPhone:

1. Go to Settings > Privacy & Security.
2. Scroll down to the bottom and tap Developer Mode.
3. Toggle it On. Your iPhone will ask to restart.

On the Apple Watch:

1. Go to Settings (on the Watch itself) > Privacy & Security.
2. Scroll to the bottom and tap Developer Mode.
3. Toggle it On. The Watch will ask to restart.

Even though the Watch connects wirelessly, you need to establish a trusted connection with the iPhone first.

1. Ensure your Mac, iPhone, and Apple Watch are all connected to the exact same Wi-Fi network.
2. Plug your iPhone into your Mac using a USB cable.
3. If prompted on the iPhone, tap Trust This Computer and enter your passcode.
4. If prompted on the Apple Watch, tap Trust and enter your passcode.

On the Mac:

1. Open Xcode on your Mac.
2. Click on the Devices tab at the top.
3. Select your connected iPhone from the left sidebar.

Hope this helps

Albert 
  Worldwide Developer Relations.

I made more progress but the operation is still failing:

• I unpaired my watch then re-paired it

• I tried many times to get the watch to show the "Developer Mode" option - it would just not show it. Finally I restarted the phone, restarted the watch, insured both on the same WiFi network as the Mac, plugged the phone back into the Mac with Xcode running, and voila - I was finally able to enable it.

• Now, the watch showed up in the Xcode Devices window, but I got the same error as I originally was getting. Now I'm suspecting Bonjour, so I restarted my Mac, and rebooted my TP-Link Archer 8 router (has latest firmware). Now, Xcode can connect to my watch!!!

It connects and tries to read the symbols, but fails with an alert in a window. Clicking on the window, I was able to copy the error:

Failed with HTTP status 400: bad request Domain: DataGatheringNSURLSessionDelegate Code: 1 User Info: { DVTErrorCreationDateKey = "2026-04-07 13:10:58 +0000"; }

Failed with HTTP status 400: bad request Domain: DataGatheringNSURLSessionDelegate Code: 1

System Information

macOS Version 26.4 (Build 25E246) Xcode 26.4 (24909) (Build 17E192) Timestamp: 2026-04-07T09:10:58-04:00

I keep trying - disconnected the USB cable from Mac to iPhone. Now I get a different error sequence - Xcode connects, fails with a "transport error", and retries. It's now in a loop:

PS: every device has the latest software on it: Mac, iPhone, iWatch and router.

Thank you for your response. Upon reviewing the errors, this should not occur. However, there may be more experienced Apple Watch engineers who have identified this error and can provide a solution.

For my understanding an HTTP 400 (Bad Request) means the network request Xcode made to the servers was rejected. If your developer account session has expired in Xcode's settings, the request to download the symbols might be sent with an invalid authentication token, resulting in a 400 error.

1. Open Xcode and go to Xcode > Settings > Accounts.
2. Select your Apple ID on the left.
3. Click the - (minus) button at the bottom to remove it.
4. Click the + (plus) button and sign back in.
5. Restart Xcode and see if it successfully fetches the symbols.

If you are using a VPN a corporate proxy, or custom DNS/firewall software, it might be intercepting and modifying Xcode's network request to Apple's servers, causing Apple to reject it as a Bad Request.

Let me know if you get past the 400 error, hopefully other engineers have better suggestions, if the steps above do not help. Let’s file a bug as this should be taken care to avoid issues for developers. Let me know and I’ll send you the info to file a bug.

Albert 
  Worldwide Developer Relations.