Unable to process your request. Please verify if the name and value is appropriate for the "xmlData" parameter

I am trying to use the insertRecords method of the crm api. I am passing the xml in the url as suggested in other posts I came across. This is the code that I am using (I changed the first 7 byts of my auth token to start in the example - I am able to execute a getRecords so I know my auth token is correct):

Dim url As String = " https://crm.zoho.com/crm/private/xml/Leads/insertRecords?authtoken=*******16f2eac78e269f1648eb4a93c&scope=crmapi&xmlData=<Leads><row&20no=%221%22>"

Dim xml_string As String = "<FL val=""Lead Owner"">" & "Jonathan Small" & "</FL>"

xml_string = xml_string & "<FL val=""Company"">" & Session("company_name") & "</FL>"

xml_string = xml_string & "<FL val=""First Name"">" & Session("first_name") & "</FL>"

xml_string = xml_string & "<FL val=""Last Name"">" & Session("last_name") & "</FL>"

Session("title") = validate_length(Session("title"))

Session("website") = validate_length(Session("website"))

Session("billing_address_2") = validate_length(Session("billing_address_2"))

xml_string = xml_string & "<FL val=""Designation"">" & Session("title") & "</FL>"

xml_string = xml_string & "<FL val=""Email"">" & Session("email") & "</FL>"

xml_string = xml_string & "<FL val=""Phone"">" & Session("phone") & "</FL>"

xml_string = xml_string & "<FL val=""Fax"">" & " " & "</FL>"

xml_string = xml_string & "<FL val=""Mobile"">" & " " & "</FL>"

xml_string = xml_string & "<FL val=""Website"">" & Session("website") & "</FL>"

xml_string = xml_string & "<FL val=""Lead Source"">" & "www.solvedsocialmedia.com" & "</FL>"

xml_string = xml_string & "<FL val=""Lead Status"">" & "Not Contacted" & "</FL>"

xml_string = xml_string & "<FL val=""Industry"">" & "Real Estate" & "</FL>"

xml_string = xml_string & "<FL val=""Street"">" & Session("billing_address_1") & "</FL>"

xml_string = xml_string & "<FL val=""Street2"">" & Session("billing_address_2") & "</FL>"

xml_string = xml_string & "<FL val=""City"">" & Session("billing_city") & "</FL>"

xml_string = xml_string & "<FL val=""State"">" & Session("billing_state") & "</FL>"

xml_string = xml_string & "<FL val=""Zip Code"">" & Session("billing_zip_code") & "</FL>"

xml_string = xml_string & "<FL val=""Country"">" & " " & "</FL>"

xml_string = xml_string & "<FL val=""Description"">" & " " & "</FL>"

xml_string = xml_string & "<FL val=""Zip Code"">" & Session("billing_zip_code") & "</FL>"

xml_string = xml_string & "<FL val=""Color"">" & Session("color") & "</FL>"

xml_string = xml_string & "<FL val=""Community"">" & Session("community") & "</FL>"

xml_string = xml_string & "</row></Leads>"

xml_string = xml_string.Replace("@", "%40")

xml_string = xml_string.Replace(" ", "%20")

xml_string = xml_string.Replace("""", "%22")

url = url & xml_string

Dim returned_xml As String = GetHtmlPage(url)

If InStr(returned_xml, "Unable to process your request") > 0 Then

return_value = False

errorlbl2.Text &= "There was a problem adding you to our system. Please try again in a few minutes<br />"

Else

return_value = True

End If

Shared Function GetHtmlPage(ByVal strURL As String) As String

Dim strResult As String = ""

Dim objResponse As WebResponse

Try

Dim objRequest As WebRequest = HttpWebRequest.Create(strURL)

objResponse = objRequest.GetResponse()

Using sr As New StreamReader(objResponse.GetResponseStream())

strResult = sr.ReadToEnd()

sr.Close()

End Using

Catch ex As Exception

strResult = ex.Message

End Try

Return strResult

End Function

The final string that gets built looks like this:

https://crm.zoho.com/crm/private/xml/Leads/insertRecords?authtoken=*******16f2eac78e269f1648eb4a93c&scope=crmapi&xmlData=<Leads><row&20no=%221%22><FL%20val=%22Lead%20Owner%22>Jonathan%20Small</FL><FL%20val=%22Company%22>1966</FL><FL%20val=%22First%20Name%22>jonathan</FL><FL%20val=%22Last%20Name%22>small</FL><FL%20val=%22Designation%22>%20</FL><FL%20val=%22Email%22>xjonathn6%40icloud.com</FL><FL%20val=%22Phone%22>516-987-6112</FL><FL%20val=%22Fax%22>%20</FL><FL%20val=%22Mobile%22>%20</FL><FL%20val=%22Website%22>%20</FL><FL%20val=%22Lead%20Source%22>www.solvedsocialmedia.com</FL><FL%20val=%22Lead%20Status%22>Not%20Contacted</FL><FL%20val=%22Industry%22>Real%20Estate</FL><FL%20val=%22Street%22></FL><FL%20val=%22Street2%22>%20</FL><FL%20val=%22City%22></FL><FL%20val=%22State%22></FL><FL%20val=%22Zip%20Code%22></FL><FL%20val=%22Country%22>%20</FL><FL%20val=%22Description%22>%20</FL><FL%20val=%22Zip%20Code%22></FL><FL%20val=%22Color%22>Golden%20Sand</FL><FL%20val=%22Community%22>1</FL></row></Leads>

Any assistance would be greatly appreciated as my development has come to a complete standstill.

Thank you,

Jonathan