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

Be careful if you skip installs. I accidentally changed Skip Install on the main target, when i meant to change it on a dependency . When changing it back I had to do a clean.