xamarin Android.Util.AndroidRuntimeException: Activity{x} did not call through to super.onStart()
<p>I get this error for the code shown below and don't know why.
my code is:</p>

<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code> protected override void OnStart()
        {            
            if (WCHSBMobileApplication.Current.SuperBillObject == null)
            {
                AddSuperBill();
            }
            else
            {
                EditSuperBill();
            }
        }</code></pre>
</div>
</div>
</p>

<p>what can I do?</p>