FBSOpenApplicationErrorDomain error 1

Question

I'm trying to run my iOS app that was migrated from Swift 1.2 to Swift 2.0 in Xcode 7 using iPhone Simulator (any), I'm getting the following error:

The operation couldn’t be completed. (FBSOpenApplicationErrorDomain error 1.)

I already tried to reset simulator settings and content, quit Xcode, clean project, etc.

Answer 1

I had the same error after updating Xcode to v7.0. After few hours struggling, I found that there was some empty environment variable setup to be passed for Run action in my active scheme (have no idea why it was there). Removing this empty environment variable resolved the issue immediately.

Answer 2

This error happens when a previous run of the app is still alive in the background, even if you clicked "Stop" in Xcode. Try manually killing the app in simulator itself: cmd+shift+H twice to open up running apps, drag up your app to kill it. Note cmd+shift+H is the shortcut to go to homescreen. Then start the new run and it should work fine :)

Answer 3

1. Simulator->Reset Content and Settings
2. Quit Simulator
3. Run the test cases again