Apple Watch app won't re-install after being deleted on iOS 8.2, just hangs on launch screen

Question

I can install my Apple Watch app (that is in production) on my watch and it loads just fine the first time. If I uninstall it, and re-install it, it installs fine, but when I tap on the icon it just hangs. It has the loading indicator and the name of the app and it won't ever load.

Here is the error from the device log:

Jul 6 15:20:23 xxxxx-iPhone companionappd[417] <Notice>: (Error) WatchKit: <SPApplicationManager.m __56-[SPApplicationManager beginUsingPlugin:withCompletion:]_block_invoke264:392> * * * After 10.0 secs, beginUsing: hasn't called us back for plugin with beginUsingInstanceUUID <__NSConcreteUUID 0x127e18800> 53259124-xxxx-454F-xxxx-FD013Dxxxxxx

Jul 6 15:20:23 xxxxx-iPhone companionappd[417] <Notice>: (Warn ) WatchKit: <SPApplicationManager.m __83-[SPApplicationManager getOrBeginActivePlugInForApplication:setupBlock:completion:]_block_invoke_2319:478> Unable to start plugin com.xxxxx.watchkitextension 0x127e887c0 with identifier com.xxxxx.watchkitapp (Error Domain=com.apple.watchkit.errors Code=17 "PKPlugin beginUsing: never called back" UserInfo=0x127d62b90 {NSLocalizedDescription=PKPlugin beginUsing: never called back})

Jul 6 15:20:23 xxxxx-iPhone companionappd[417] <Notice>: (Error) WatchKit: <SPCompanionAppServer.m __51-[SPCompanionAppServer sendToRemoteInterface:call:]_block_invoke492:860> activePlugInForIdentifier: returned nil for application com.xxxxx.watchkitapp

I can't figure out what is going on. Is this an SDK/OS issue that is out of my hands? Has anyone seen this?

UPDATE: I just read (and confirmed) on the forums that if you restart both the watch and the phone, the watch app will load without issue. Sounds like an OS bug to me.

UPDATE 2: Got a response from a radar I filed:

I guess its good to confirm they knew about it and fixed it.

Answer 1

This definitely sounds like an OS error, as your log even says Unable to start plugin com.xxxxx.watchkitextension. That is nothing you can do anything about. I was going to say that you should probably just restart your simulator inorder for it to work properly again. Another option would have been to just reset your simulator and hardware, however that is only the worst case scenario. As the above person said, you should file a radar here. Lastly, you could try to install it on a real device and then delete it in order to check if it's an simulator bug or it will also happen on normal devices. There's a good chance it's just the simulator being unable start up the app. Hope that helps, Julian