XIB File opens like an XML in XCode but opens correctly with Interface Builder

Question

When I double-click my file StartWindow.xib in Xcode 4, it does not open into the integrated Interface Builder; it opens like a XML file. I can open all other xib files and they

Answer 1

Go to the File Inspector after selecting the nib file. Under Identity and Type, select the drop down list for File Type and choose the topmost element Default - com.apple....