title: System.ArgumentNullException: Value cannot be null. Parameter name: value
body: <p>I have no idea where the <code>value</code> parameter comes from.</p>
  
  <p>View: <code>Ajax.BeginForm</code> inquiry:</p>
  
  <pre><code>@Html.DropDownListFor(model =&gt; model.EXPENSE_REPORTABLE, new SelectList(
                      new[] 
                      { 
                          new { Value = "true", Text = "Yes" },
                          new { Value = "false", Text = "No" },
                      },
                      "Value",
                      "Text",
                      Model
                  ),
                  "-- Select --")
  </code></pre>
  
  <p>After I choose yes or no in the drop down list, a partial view will be rendered for displaying data in a WebGrid (<code>grid</code> is an instance of <code>WebGrid</code>). One of the columns throws the error:</p>
  
  <pre><code>grid.Column("expenseReportable","Expense Reportable?",format:@&lt;text&gt;
  &lt;span class="display-mode"&gt;@item.EXPENSE_REPORTABLE  &lt;/span&gt; &lt;!--error here --&gt;
  @Html.RadioButton("GridCol_Expense", (Nullable&lt;bool&gt;)item.EXPENSE_REPORTABLE, true, new { @class="edit-mode"}) Yes        
  @Html.RadioButton("GridCol_Expense", (Nullable&lt;bool&gt;)item.EXPENSE_REPORTABLE, false, new { @class="edit-mode"}) No
                  &lt;/text&gt;, style:"col1Width"),
  </code></pre>
  
  <p>Model property:</p>
  
  <pre><code>public Nullable &lt;bool&gt; EXPENSE_REPORTABLE {get; set;}
  </code></pre>
  
  <p>InnerException: <code>null</code></p>
  
  <p>Exception Message:</p>
  
  <blockquote>
    <p>Value cannot be null. Parameter name: value</p>
  </blockquote>