Working on my project today and double-clicked on a XIB file in my Solution view. In the past it always started Xcode and brought me right to the IB Builder. Last few days I did this and it still worked, but always gave me some Xcode error that I ignored.
HOWEVER...
This time I doubled-clicked on a XIB in the Solution Explorer and got the usual error, but XCode never came up automatically as before. And all of my 30 or so XIB files are no longer showing up in the Solution View. The files still exist on disk, and the project still builds, even after a Clean and Rebuild.
So what happened???