MainWindow.xib View Not Showing in IB

[C6Silver]

I know this used to work...

When I create a new app with the "Tab Bar Application Template" and then click on the MainWindow.xib to go to IB, the view window doesn't display. I can get the library, the inspector, and the window that has "file owner, first responder, etc.", but not the view. I do get the view for the xib files it creates and I do get it with other templates. What could be the issue here? I have tried this several times with new projects making no changes and immediately clicking on the MainWindow.xib after creation.

IB version 3.2.3.

Thanks!