Simulator error FBSSystemServiceDomain code 4

Question

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) 

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?

Answer 1

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

Alternatively, you could quit and reopen the Simulator.

Answer 2

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