title: JSON Serialize - Object reference not set to an instance of an object
body: <p>I am using the following class -</p>
  
  <pre><code>    public class RequestObject
  {
      public string loanPurpose { get; set; }
      public string occupancy { get; set; }
      public string propertyType { get; set; }
      public string condoStyle { get; set; }
      public int purchasePrice { get; set; }
      public string propertyValue { get; set; }
      public double loanAmount { get; set; }
      public int loanAmountPCT { get; set; }
      public string secondLien { get; set; }
      public string maxLimit { get; set; }
      public string curBalance { get; set; }
      public string disposition { get; set; }
      public string openedDate { get; set; }
      public int zipcode { get; set; }
      public string creditScore { get; set; }
      public string loanProgram { get; set; }
      public string pleaseSpecify { get; set; }
      public string orgPurchasePrice { get; set; }
      public string cmYearStart { get; set; }
      public string escrowAccount { get; set; }
      public string unitsNo { get; set; }
      public string lockPeriod { get; set; }
      public string payoffAmount { get; set; }
      public string f1OptStatus { get; set; }
  }
  </code></pre>
  
  <p>I am building an object from the class like so - </p>
  
  <pre><code>            var jsonObject = new RequestObject
          {
              loanPurpose = "Purchase",
              occupancy = "Primary Residence",
              propertyType = "Townhouse",
              condoStyle = "Attached",
              purchasePrice = purchasePrice,
              propertyValue = null,
              loanAmount = actualLoanAmount,
              loanAmountPCT = loanPercent,
              secondLien = null,
              maxLimit = null,
              curBalance = null,
              disposition = null,
              openedDate = null,
              zipcode = zipCode,
              creditScore = "780 +",
              loanProgram = "30 Year Fixed",
              pleaseSpecify = null,
              orgPurchasePrice = null,
              cmYearStart = null,
              escrowAccount = "With Escrow Account",
              unitsNo = null,
              lockPeriod = "30 Days",
              payoffAmount = null,
              f1OptStatus = "No"
          };
  </code></pre>
  
  <p>I am then calling the Serialize method -</p>
  
  <pre><code>            var json = request.JsonSerializer.Serialize(jsonObject);
  </code></pre>
  
  <p>When I execute my application, I get 'Object reference not set to an instance of an object' on the Serialize method line.</p>
  
  <p>I thought I am building the object correctly. What is going wrong?</p>
  
  <p>Thank you!</p>