I often use an ItemsControl to generate ToggleButtons in the ribbon using ObjectDataProvider for some enum value.
The version 11 of Fluent.Ribbon crashes when doing it, while the version 10 (and all the previous ones, I guess) were working fine,
I put a small example in https://github.com/YetAnotherCodeMaker/FluentRibbonSamples/tree/main/V11RibbonToggleButtonIssue.
Visual Studio 17.13.3, .NET 9.0.3.