In order to achieve your requirement you can try to minimize the ribbon view control when you select the tab with the empty content. Basically you can subscribe to the SelectionChanged event of RadRibbonView and inside its handler set the ribbon's IsMinimized property to true.
Here is a sample in code:
sender, RadSelectionChangedEventArgs e)
(e.AddedItems.Count > 0)
var tab = e.AddedItems
Also, can you please tell me how you are collapsing the ribbon in your implementation? This will allow me to understand it better and assist you further with the app's crash.
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