Now I have solved it, below are the steps to follow:
Step I Right click on your StoryBoard and openAs "SourceCode"
Step II
Step III Now you are done. open storyboard as interfaceBuilder
Question
I was porting to my existing project to iOS 7 in Xcode 5 framework, But when I opening again in Xcode 4.x.x its giving me this error.
Solution
Now I have solved it, below are the steps to follow:
Step I Right click on your StoryBoard and openAs "SourceCode"
Step II
Step III Now you are done. open storyboard as interfaceBuilder
OTHER TIPS
In Xcode 5, the file properties on the right inspector, you can set under what version of Xcode the file should open. You can set this to Xcode 4.6 and it will open in older versions of Xcode.