Issue finding custom attributes

I am trying to find all the methods in my assembly that have a custom attribute. I have tried the other solutions posted on here, but I cant seem to get any results on which methods have the attribute type I am looking for. Hopefully someone can point out what I am doing wrong.

[AttributeUsage(AttributeTargets.All)]
public class RPCAttributeType : Attribute
{
    private string _name;
    private double _version;

    public double Version
    {
        get { return _version; }
        set { _version = value; }
    }

    public string Name
    {
        get { return _name; }
        set { _name = value; }
    }

    public RPCAttributeType(string name)
    {
        Name = name;
        Version = 1.0;
    }
}


    public RPCModule()
    {
        try
        {



            Assembly assembly = Assembly.ReflectionOnlyLoad("Parser");


            var results = CustomAttributeData.GetCustomAttributes(assembly);

            ShowAttributeData(results);


        }
        catch(Exception ex)
        {
            Console.WriteLine(ex.Message);

        }

    }

    [RPCAttributeType("Select")]
    public DataRow[] Select(string expression)
    {
        return MessageDataTable.Select(expression);
    }