public void ShowError(string message, Action closingCallback)
{
if (_LastCallBack != null)
{
throw new InvalidOperationException("The error screen has already been opened.");
}
_LastCallBack = closingCallback ?? throw new ArgumentNullException(nameof(closingCallback));
_ErrorScreen.Message = message ?? throw new ArgumentNullException(nameof(message));
_ErrorScreen.Open();
}
