Q:

AppleScript data is not supported in Xcode 4

I'm migrating a GUI-application from XCode 3 to XCode 4. The source-code is only AppleScript. When I'm opening the a NIB-file the following message pops up:

AppleScript data is not supported in Xcode. The AppleScript data in this NIB file has been removed.

When I start the application its main-window just stays blank.
What can I do about this? I want to be able to edit my application, its GUI in XCode 4.5 and build it there.
Here's a screenshot of the message-box:

A:

You could try and copying the window in Xcode 3 and then paste it into the Xcode 4 project.
I have not tried this myself for this reason. But have done similar in the past. 
I found the suggestion of using this method for this problem though here

