Cannot run app on real Apple Watch

When this happened to me, I fixed the issue by:

1. Making sure there are no problems with your Main.storyboard and it has an initial view controller.
2. Deleted app on phone
3. Rebooted phone
4. Rebooted watch
5. Quit xcode and rebooted mac

You could build the app to iPhone first, wait the watch app sync to watch. (Or you could sync it in companion by turn off and turn on the install switch manually)

Then keep the app running on watch, select Xcode->Debug->Attach to Process->XXXXX Extension(the name of your watch extension)

After a while you should be able to debug the watch app.

After restarting all my devices twice to no avail, here are some tips that sometimes solve the issue. (This whole thing is a headache.) I usually use the combination of these 3 things and it works 90% of the time.

1. Build for a simulator and then switch back to a real device again.

2. Switch the Info/Launch scheme setting to "Wait for the executable to be launched", run the project and then switch back to "Automatically".

   

3. Delete the Derived Data folder located under ~/Library/Developer/Xcode/DerivedData.