thanks for the very fast answer.
As far as i can see, the error ist raised in UnityBootstrapper.
// In UnityBootstrapper:
protected override void InitializeModules()
base.InitializeModules(); // Error here
catch (Exception e)
Logger.Log("Ribbon1 was successfully initialized.",
To update the Projects i use Nuget/Update, so, the 'old' References should be removed and replaced by the new ones.