Programmatically Set NTFS File System Folder Permissions

I am getting the error "The security ID structure is invalid." When running
this code.

Sub SetPermissions( ByRef vPath As String, ByVal UserName As String)
Dim objADsSec As ADsSecurity
Dim objSecDes As SecurityDescrip tor
Dim objDAcl As AccessControlLi st
Dim objAce As Object
Dim objAce1 As AccessControlEn try
Dim objAce2 As AccessControlEn try
Dim objSId As ADsSID
Dim objSIdHex As Object

UserName = "molnarc"
objADsSec = New ADsSecurity
objSecDes = CType(objADsSec .GetSecurityDes criptor("FILE://" &
vPath), SecurityDescrip tor)
objDAcl = CType(objSecDes .DiscretionaryA cl, AccessControlLi st)

objSId = New ADsSID
objSId.SetAs(AD SSECURITYLib.AD S_SID_FORMAT.AD S_SID_SAM,
CStr(UserName))
objSIdHex = objSId.GetAs(AD SSECURITYLib.AD S_SID_FORMAT.AD S_SID_SDDL)

' Add a new objAce so that the User has Full Control on NTFS Files.
objAce1 = New AccessControlEn try
objAce1.Trustee = CStr(objSIdHex)
objAce1.AccessM ask = ActiveDs.ADS_RI GHTS_ENUM.ADS_R IGHT_GENERIC_AL L
objAce1.AceType = ActiveDs.ADS_AC ETYPE_ENUM.ADS_ ACETYPE_ACCESS_ ALLOWED
objAce1.AceFlag s = ActiveDs.ADS_AC EFLAG_ENUM.ADS_ ACEFLAG_INHERIT _ACE
Or ActiveDs.ADS_AC EFLAG_ENUM.ADS_ ACEFLAG_INHERIT _ONLY_ACE Or 1
objDAcl.AddAce( objAce1)

' Add a new objAce so that the User has Full Control on NTFS Folders.
objAce2 = New AccessControlEn try
objAce2.Trustee = CStr(objSIdHex)
objAce2.AccessM ask = ActiveDs.ADS_RI GHTS_ENUM.ADS_R IGHT_GENERIC_AL L
objAce2.AceType = ActiveDs.ADS_AC ETYPE_ENUM.ADS_ ACETYPE_ACCESS_ ALLOWED
objAce2.AceFlag s = ActiveDs.ADS_AC EFLAG_ENUM.ADS_ ACEFLAG_INHERIT _ACE
Or 1
objDAcl.AddAce( objAce2)

objSecDes.Discr etionaryAcl = objDAcl
' Set Permissions on the NTFS folder.
objADsSec.SetSe curityDescripto r(objSecDes) '<-- Error happens here

End Sub

I have even tried this and still get the error.

Sub SetPermissions( ByRef vPath As String, ByVal UserName As String)
Dim objADsSec As ADsSecurity
Dim objSecDes As SecurityDescrip tor
Dim objDAcl As AccessControlLi st
Dim objAce As Object
Dim objAce1 As AccessControlEn try
Dim objAce2 As AccessControlEn try
Dim objSId As ADsSID
Dim objSIdHex As Object

UserName = "molnarc"
objADsSec = New ADsSecurity
objSecDes = CType(objADsSec .GetSecurityDes criptor("FILE://" &
vPath), SecurityDescrip tor)
objADsSec.SetSe curityDescripto r(objSecDes) '<-- Error happens here

end sub

Any clue as what i could be doing wrong?