Changed SegmentControls now my mainwindow will not load

happily developing and testing my application. The, changed some segment controls to radio buttons, and now it won’t load my main window? The app just says compiling code then stops at end of the ‘open’ event within the ‘app’?

How can I get this to work?

I’ve had that happen a couple of times after changing some things around, it could be a bug.

Easy fix though, just click on App, then in the inspector, re-assign your default window.