FBSOpenApplicationErrorDomain error 3 when trying to launch a watch kit app on a physical device

Question

I get the same problem that is described in this question. However, that problem dealt with the iOS simulator, not a physical device.

I'm not using the iOS Simulator. I'm deploying to an iPhone + Apple Watch.

If I attempt to run it on the simulator, it works just fine.

On the "Running WatchKit App on Apple Watch" build step, I get the following error:

Error Launching 'WatchKit Extension'
The operation couldn’t be completed. (FBSOpenApplicationErrorDomain error 3.)

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What I've tried:

I tried reseting the iOS simulator and then running it on the device (not sure how that would help), but I still got the same error message.

I tried going in to iOS Settings > General > Device Management and ensuring that the app is "Verified".

Restarting Xcode didn't help either.

Deleting the app and reinstalling doesn't help.

I tried running the iOS app once to ensure there are no permissions issues on that end.

Xcode: 7.2
iPhone: iOS 9.2
Apple Watch: watchOS 2.1

Answer 1

This was a permissions issue on the Apple Watch.

To fix:

1. Launch the app once manually (not through Xcode).

   You will see the following message:

   Untrusted App Developer
   Do you trust the developer "..." to run apps on your Apple Watch?
   [Trust]
   [Don't Trust]

2. Tap Trust.

3. Now you can run the app through Xcode with no issues.