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I'm trying to run an app in the simulator but get this error message:

Unable to run app in Simulator
An error was encountered while running (Domain = FBSSystemServiceDomain, Code = 4)

Screenshot for error

I've not seen any previous references to this from googling around.

Its using XCode 6 Beta, the app is in Swift which links to a Obj-C static library. It runs fine on the device.

Any ideas?

Jayprakash Dubey
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Gruntcakes
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6 Answers6

525

Go to the iOS Simulator menu and select Reset Content and Settings.

Alternatively, you could quit and reopen the Simulator.

enter image description here

Umar Farooq
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Marie
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    Same solution works for not only for the Beta version but also for the final Xcode 6. thx! –  Sep 25 '14 at 10:08
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    Still broken in Xcode 6.0.1, this workaround still works (thankfully) -- Apple testing FTW. – Adam Oct 11 '14 at 14:10
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    Resetting contents and settings and resetting contents and settings does not help the situation. Just retry and eventually you'll win the race condition. This issue is discussed in the Apple Developer Forums and Xcode Release Notes. – Jeremy Huddleston Sequoia Nov 15 '14 at 20:07
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    Ran into this problem with xcode 6.1.1, but this fixed the issue. – Edwin Liang Dec 03 '14 at 16:41
  • This worked like a charm! Just closing and reopening didn't work for me. Needed to reset the content and settings. Thanks – Phil Jan 26 '15 at 09:50
  • thanks. I was having trouble in xCode 6.1.1 but reseting fixed it. – Natasha Jun 04 '15 at 08:16
26

It's enough to quit and re-open the Simulator, this has been verified in the Xcode 6.0.1 release.

Alex Zavatone
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Francesco
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  • I hope you wanted to say "quit" – Rashmi Ranjan mallick Sep 23 '14 at 11:43
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    Re-launching the simulator is not required. Just try again. This is discussed in the Xcode release notes as a known issue. – Jeremy Huddleston Sequoia Nov 15 '14 at 20:05
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    Just trying again does not work for me, neither re-launching the simulator. When the issue occurs I need to relaunch Xcode such as I'm able to launch again my app on the simulator. – Lisarien Dec 10 '14 at 09:06
  • Restarting Simulator worked for me on Xcode 6.1.1. IMO, better than accepted answer, since it's not always desirable to erase all apps from simulator, e.g. where you have a lot of apps and want to keep some in a pre-installed state. – David James Feb 12 '15 at 10:59
2

This issue is discussed in the Xcode 6 Release Notes

Testing on iOS Simulator may produce an error indicating that the application could not be installed or launched. Re-run testing or start another integration. (17733855)

And is also discussed in my sticky post in the Apple Developer Forums for iOS Simulator Debugging

"(Domain = FBSOpenApplicationErrorDomain, Code = 4)", "(Domain NSPOSIXErrorDomain, Code = 3"), "Domain=IDEUnitTestsOperationsObserverErrorDomain Code=3", "Lost Connection to ...", "Debugger disconnected", or app getting SIGKILLed soon after launch Upon installation of an app, SpringBoard will SIGKILL that app's process in order to force a relaunch of the app with the new executable. The problem is that there is a race condition whereby SpringBoard may accidentally SIGKILL a new process that we just launched rather than the old process. Which of the various error messages you get depends on exactly when in the launch process the SIGKILL was delivered. Normally, this shouldn't happen, so the advise is to just try again (sorry =/). If you find that this happes to you all the time or more frequently than you can tollerate, we are incredibly sorry. We are aware that systems with slower disk I/O will see this happen more frequently than faster systems, so if you are using an NFS home directory, you may want to create a local directory for your simulator data and setup a simlink to it from ~/Library/Developer/CoreSimulator

Note that the original question is about domain FBSSystemServiceDomain whereas my post on devforums mentions FBSOpenApplicationErrorDomain. FBSSystemServiceDomain was used in earlier versions of iOS 8.0 betas.

Jeremy Huddleston Sequoia
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0

You can either Reset Content and Setting or just close iOS Simulator and relaunch.

user1824791
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0

None of the solutions worked for me including the accepted answer of "Reset Content and Settings".

The only way I was able to get it to work was by downloading a previous iOS simulator version which let me install the app.

Steve
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-2

I suggest you to use stable version of Xcode 6.1. 

FBSOpenApplicationErrorDomain, code =4 error suggests it is an error from 
cached data on the simulator.

There are three possible solutions :

  1. Clean simulator. Use (Command + Shift + k) as shortcut key or goto Product -> Clean

  2. Quit simulator and relaunch it.

  3. Open simulator. Select iOS simulator -> Reset contents and settings...

Screenshot for step 3

Jayprakash Dubey
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