FBSOpenApplicationErrorDomain code =4 error

Question

When I\'m trying to run iOS application in Xcode 6 in iPhone 6 simulator, I\'m getting error Unable to run app in Simulator.

And error code is:

Answer 1

As mentioned in the Xcode release notes, this error (along with a couple others) results from a timing bug. The workaround is to just retry.

See https://developer.apple.com/library/prerelease/mac/releasenotes/DeveloperTools/RN-Xcode/Chapters/xc6_release_notes.html#//apple_ref/doc/uid/TP40001051-CH4-SW1

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.

Also see:

https://devforums.apple.com/thread/248879?tstart=0