Cannot convert null to a value type JSON error

I am getting error 'Cannot convert null to a value type' when trying to deserialize JSON response into class object
I have the following code in C#

var client2 = new RestClient("https://portal.greeneis.com/v4_6_release/apis/3.0/company/contacts/"+CU.BillingContactId);
var request2 = new RestRequest(Method.GET);
request2.RequestFormat = DataFormat.Json;

request2.AddHeader("cache-control", "no-cache");
request2.AddHeader("authorization", "Basic " + token);

IRestResponse response2 = client2.Execute(request2);
JavaScriptSerializer oJS2 = new JavaScriptSerializer();

var oRootObject2 = oJS2.Deserialize<ContactClass.Rootobject>(response2.Content);

With C# class as

public class ContactClass
    {

        public class Rootobject
        {
            public int id { get; set; }
            public string firstName { get; set; }
            public string lastName { get; set; }
            public Type type { get; set; }
            public Company company { get; set; }
            public Site site { get; set; }
            public string addressLine1 { get; set; }
            public string addressLine2 { get; set; }
            public string city { get; set; }
            public string state { get; set; }
            public string zip { get; set; }
            public string country { get; set; }
            public Relationship relationship { get; set; }
            public object department { get; set; }
            public bool inactiveFlag { get; set; }
            public string defaultMergeContactId { get; set; }
            public string securityIdentifier { get; set; }
            public string managerContactId { get; set; }
            public string assistantContactId { get; set; }
            public string title { get; set; }
            public string school { get; set; }
            public string nickName { get; set; }
            public bool marriedFlag { get; set; }
            public bool childrenFlag { get; set; }
            public string significantOther { get; set; }
            public string portalPassword { get; set; }
            public int portalSecurityLevel { get; set; }
            public bool disablePortalLoginFlag { get; set; }
            public bool unsubscribeFlag { get; set; }
            public string gender { get; set; }
            public string birthDay { get; set; }
            public string anniversary { get; set; }
            public string presence { get; set; }
            public string mobileGuid { get; set; }
            public string facebookUrl { get; set; }
            public string twitterUrl { get; set; }
            public string linkedInUrl { get; set; }
            public bool defaultBillingFlag { get; set; }
            public Communicationitem[] communicationItems { get; set; }
            public _Info4 _info { get; set; }
            public string customFields { get; set; }
        }

        public class Type
        {
            public int id { get; set; }
            public string name { get; set; }
            public _Info _info { get; set; }
        }

        public class _Info
        {
            public string type_href { get; set; }
        }

        public class Company
        {
            public int id { get; set; }
            public string identifier { get; set; }
            public string name { get; set; }
            public _Info1 _info { get; set; }
        }

        public class _Info1
        {
            public string company_href { get; set; }
        }

        public class Site
        {
            public int id { get; set; }
            public string name { get; set; }
            public _Info2 _info { get; set; }
        }

        public class _Info2
        {
            public string site_href { get; set; }
        }

        public class Relationship
        {
            public int id { get; set; }
            public string name { get; set; }
            public _Info3 _info { get; set; }
        }

        public class _Info3
        {
            public string relationship_href { get; set; }
        }

        public class _Info4
        {
            public DateTime lastUpdated { get; set; }
            public string updatedBy { get; set; }
            public string communications_href { get; set; }
            public string notes_href { get; set; }
            public string tracks_href { get; set; }
            public string portalSecurity_href { get; set; }
            public string image_href { get; set; }
        }

        public class Communicationitem
        {
            public int id { get; set; }
            public Type1 type { get; set; }
            public string value { get; set; }
            public string extension { get; set; }
            public bool defaultFlag { get; set; }
            public string communicationType { get; set; }
        }

        public class Type1
        {
            public int id { get; set; }
            public string name { get; set; }
            public object _info { get; set; }
        }

    }

var oRootObject2 = oJS2.Deserialize<ContactClass.Rootobject>(response2.Content); line is throwing error that ' Cannot convert null to a value type.'

Lots of solutions online suggesting creating custom Class with nullable types but this won't work for me. I have no control over the Json

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2 Answers