Using enum in ConverterParameter

ArsenMkrt's answer is correct,

Another way of doing this is to use the x:Static syntax in the ConverterParameter

<Button ...
        Visibility="{Binding Path=CurrentAuthenticationLevel,
            Converter={StaticResource AuthenticationToVisibility},
            ConverterParameter={x:Static local:AuthenticationEnum.Administrator}}"/>

And in the converter

public class AuthenticationToVisibility : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        AuthenticationEnum authenticationEnum = (AuthenticationEnum)parameter;
        //...
    }
}

User

 (AuthenticationEnum)Enum.Parse(typeof(AuthenticationEnum),parameter)

to parse string as enumerator