Uncaught ReferenceError: Sys is not defined on ASP.NET
<p>I want use ajax on <a href="http://www.asp.net/" rel="nofollow">ASP.NET</a> platform. For that I use <a href="https://msdn.microsoft.com/en-us/library/bb398863.aspx" rel="nofollow">ScriptManager</a>. Simply I add this script with <a href="https://jquery.com/" rel="nofollow">jQuery</a> after when "<a href="https://learn.jquery.com/using-jquery-core/document-ready/" rel="nofollow">document is ready</a>".</p>

<pre class="lang-javascript prettyprint-override"><code>$(document).ready(function () {

    // sync
    {{scopeName}}_init();

    // async

    Sys.WebForms.PageRequestManager.getInstance().add_pageLoaded(function (sender, args) {
        {{scopeName}}_init();
    });

});
</code></pre>

<p>And then such a mysterious <a href="https://en.wikipedia.org/wiki/JavaScript" rel="nofollow">javascript</a> error happened.</p>

<blockquote>
  <p>Uncaught ReferenceError: Sys is not defined</p>
</blockquote>

<p>Q what I have wrong if javascript stop working after first request?</p>