AdjustTokenPrivilege c# 0x80070057

I am trying to write UEFI properties. it appears that i need to raise the token privileges. so i have used http://www.pinvoke.net/default.aspx/advapi32.adjusttokenprivileges as a guide to do this.

I keep getting the error E_Invalid Arguments

    public static void EnableDisablePrivilege(string PrivilegeName, bool EnableDisable)
    {
        //Gets the process token handle using pinvoke
        var inTokenHandle = IntPtr.Zero;
        if (!OpenProcessToken(Process.GetCurrentProcess().Handle, TokenAccessLevels.AdjustPrivileges | TokenAccessLevels.Query, out inTokenHandle))
        {
            Marshal.ThrowExceptionForHR(Marshal.GetHRForLastWin32Error());
            return;
        }

        //Enumerates the current privileges of the token handle
        var inNewState = new TOKEN_PRIVILEGES { PrivilegeCount = 1, Privileges = new LUID_AND_ATTRIBUTES[1] };

        //Attempts to lookup the inputed privilege
        LUID luid;
        if (!LookupPrivilegeValue(null, PrivilegeName, out luid))
        {
            Marshal.ThrowExceptionForHR(Marshal.GetHRForLastWin32Error());
            return;
        }
        //Adds the new privilige to the token whilst retaining all the other priviliges
        inNewState.Privileges[0].LUID = luid;
        inNewState.Privileges[0].Attributes = (uint)(EnableDisable ? 2 : 0);

        //Attempts to set the priviliges to the token handle.
        if (!AdjustTokenPrivileges(inTokenHandle, false, ref inNewState, 256, IntPtr.Zero, IntPtr.Zero))
        {
            Marshal.ThrowExceptionForHR(Marshal.GetHRForLastWin32Error());
            return;
        }
    }

    /// <summary>
    /// An LUID is a 64-bit value guaranteed to be unique only on the system on which it was generated
    /// </summary>
    [StructLayout(LayoutKind.Sequential)]
    public struct LUID
    {
        /// <summary>
        /// Low Order BIts
        /// </summary>
        public uint LowPart { get; set; }
        /// <summary>
        /// High Order Bits
        /// </summary>
        public int HighPart { get; set; }
    }


    /// <summary>
    /// The LUID_AND_ATTRIBUTES structure represents a locally unique identifier (LUID) and its attributes.
    /// </summary>
    [StructLayout(LayoutKind.Sequential)]
    public struct LUID_AND_ATTRIBUTES
    {
        /// <summary>
        /// Specifies the HIgh Order BIts and Low Order Bits Stucture
        /// </summary>
        public LUID LUID { get; set; }
        /// <summary>
        /// Specifies attributes of the LUID. This value contains up to 32 one-bit flags.
        /// </summary>
        public uint Attributes { get; set; }
    }
    /// <summary>
    /// The TOKEN_PRIVILEGES structure contains information about a set of privileges for an access token.
    /// </summary>
    [StructLayout(LayoutKind.Sequential)]
    public struct TOKEN_PRIVILEGES
    {
        /// <summary>
        /// This must be set to the number of entries in the Privileges array.
        /// </summary>
        public uint PrivilegeCount { get; set; }
        /// <summary>
        /// Specifies an array of LUID_AND_ATTRIBUTES structures. 
        /// </summary>
        public LUID_AND_ATTRIBUTES[] Privileges { get; set; }
    }

    [DllImport("advapi32", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool OpenProcessToken(
        IntPtr ProcessHandle, 
        TokenAccessLevels DesiredAccess, 
        out IntPtr TokenHandle);

    [DllImport("advapi32.dll", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool AdjustTokenPrivileges(
        IntPtr TokenHandle,
        [MarshalAs(UnmanagedType.Bool)]bool DisableAllPrivileges, 
        ref TOKEN_PRIVILEGES NewState, 
        uint BufferLengthInBytes, 
        IntPtr PreviousState, 
        IntPtr ReturnLength);

    [DllImport("advapi32.dll", SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool LookupPrivilegeValue(
        string lpSystemName, 
        string lpName, 
        out LUID lpLuid);

Calling Code: //Enable a privilege by implementing the following line in your code: Privileges.EnableDisablePrivilege("SeSystemEnvironmentPrivilege", true);

Im honestly not sure where i have gone wrong here.