Xcode 6 GM crashes when selecting the main storyboard or a xib

Question

I just downloaded the Xcode 6 GM and every time I select the main storyboard (and a specific xib) Xcode crashes.

The error to be sent to Apple contains the following

Answer 1

Was this from an earlier version of Xcode, or was it from one of the earlier Xcode 6 releases? If the latter, then the solution will be to recreate it.

You might be able to take a look inside the storyboard file and find out if it's a valid document - the file is XML based so you should be able to see if there are any missing elements or problems introduced by a merge conflict, for example. You may also be able to try deleting particular screens to see if that resolves your problem - perhaps the issue is in relation to one particular screen.

I'd also suggest checking if your objects have implemented an IBDesignable attribute and if you used that in the storyboard; if so, it might be a failure of the NSCoder to be able to restore the object from the file.