How to fix error "Could not insert new outlet connection and deleting DerivedData doesnt work"

Environment

• Xcode 7.3

Situation

• Using Storyboard, when I tried to connect IBOutlet, error "Could not insert new outlet connection and deleting DerivedData doesnt work" was shown
• And set automatic in Assistant Editor, No Result was shown, and targeted View Controller never been shown
• But targeted ViewController has been set already

I thought

• Basically valid indexing resolves any problems

Try

Indexing

• Set Index On, and automatically launch indexing
  • Command to launch it defaults write com.apple.dt.Xcode IDEIndexDisable 0

Second hand: Clear old data and retry connecting with clear Xcode

• Clear cache
  • rm -rf ~/Library/Caches/com.apple.dt.Xcode
• Clear DerivedData
  • rm -rf ~/Library/Developer/XCode/DerivedData/{project name}
• Clean Build
• Restart Xcode

Result

• Delete DerivedData and indexed, problems was solved