лок кода, с которым у меня возникают ошибки:

    public static bool Flash(Form form)
    {
        return (Win2000OrLater && FlashWindowEx(ref Create_FLASHWINFO(form.Handle, 15, uint.MaxValue, 0))); //A ref or out argument must be an assignable variable

    }

    public static bool Flash(Form form, uint count)
    {
        return (Win2000OrLater && FlashWindowEx(ref Create_FLASHWINFO(form.Handle, 3, count, 0))); //A ref or out argument must be an assignable variable
    }
    private static extern bool FlashWindowEx(ref FLASHWINFO pwfi);
    public static bool Start(Form form)
    {
        return (Win2000OrLater && FlashWindowEx(ref Create_FLASHWINFO(form.Handle, 3, uint.MaxValue, 0))); //A ref or out argument must be an assignable variable
    }

    public static bool Stop(Form form)
    {
        return (Win2000OrLater && FlashWindowEx(ref Create_FLASHWINFO(form.Handle, 0, uint.MaxValue, 0))); //A ref or out argument must be an assignable variable
    }

    private static bool Win2000OrLater
    {
        get
        {
            return (Environment.OSVersion.Version.Major >= 5);
        }
    }

Сообщение об ошибке:

Аргумент ref или out должен быть назначаемым