When I try to run the Xcode simulator I get the error 'Stop “(null)”?'

ios xcode ios-simulator xcode7
Caleb Kleveter picture Caleb Kleveter · Sep 21, 2015 · Viewed 8.3k times · Source

I just updated to Xcode 7 and ran an app on a live device. Now for some reason, I get an error when I try to run an app in a simulator. 

Stop “(null)”? 
An instance of “(null)” is already running. Choose “Stop” to terminate and launch a new instance.

Image of the error pop-up in Xcode

When I press the stop button it grays out, as in the screen shot, but nothing happens. I have tried resetting the content and settings on the simulator, but that didn't help.

Answer

joels picture joels · Sep 23, 2015

Getting this as well with Xcode 7.

I've been following these simple steps to avoid seeing the error:

  1. Build your app.
  2. Run your app.

Annoying, and not a solution, but I think this is a bug within Xcode 7.

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