XCode cannot run using the selected destination.

[Dreamspinner]

Google hasn't helped with this one. I found a lot of hits on similar issues, but no solution. Suddenly, I'm getting the following on a project I've been working on for a couple of weeks.

My build settings are below also.

I haven't been able to figure out what/where destination is. I was trying to change the name of my app. In Build Settings I changed Packaging->Product Name. Changing it back didn't clear the error.

Well it happened again, on another project, after I changed the app's name. I've tried pretty much every SDK and architecture, I've deleted the scheme and auto-created a new on, done a clean, closed the project, closed Xcode and restarted re-opened the project and no joy. Xcode 4.5.2 running on a MacBook Pro.