Parser Error: Unknown server tag atlas:ScriptManager

Problem

You get this error when running your application:

Parser Error

Description: An error occurred during the parsing of a resource required to service this request. Please review the following specific parse error details and modify your source file appropriately.

Parser Error Message: Unknown server tag 'atlas:ScriptManager'.

Source Error:

Line 56:     <body id="Body1" runat="server" class="pageBackground">
Line 57:     <form id="Form1" method="post" runat="server">
Line 58:         <atlas:ScriptManager ID="scriptManager1" runat="server"/>
Line 59:         <BaseClasses:ScrollCoordinates id="ScrollCoordinates" runat="server"> </BaseClasses:ScrollCoordinates>
Line 60:         <BaseClasses:BasePageSettings id="PageSettings" runat="server"> </BaseClasses:BasePageSettings>

This error occurs when your application contains ASPX pages that refer to an older version of the Ajax DLL that predates Microsoft's official Ajax 1.0 release in February 2007. Most likely you installed Atlas or a beta release of Ajax and modified your ASPX pages directly to use the <atlas:ScriptManger> tag.

Iron Speed Designer V4.2 and later builds applications that use the newer, officially released Ajax 1.0 DLL (or later) from Microsoft for .NET Framework 2.0 / 3.0 applications. Iron Speed Designer V4.2 and later automatically migrates your application to use the officially released Ajax version, replacing your older pre-release Ajax or Atlas DLL. It uses <asp:ScriptManager> tags and not the older <atlas:ScriptManager> tags. At run-time, your application is not able to find the older Atlas DLL referenced in the <atlas:ScriptManager> tag.

Solution

Step 1: Rebuild your application (Build, Rebuild All). This will update all ASPX pages in your application, potentially replacing the <atlas:ScriptManager> tags with the newer <asp:ScriptManager> tags.

Step 2: Run your application and determine if the error still occurs. If the error no longer occurs, then your problem is solved.

Step 3: If the error still occurs, delete the <atlas:ScriptManager> tag from your ASPX pages and replace them with:

<asp:ScriptManager ID="scriptManager1" runat="server" EnablePartialRendering="True" EnablePageMethods="True" />

Step 4: Build and run your application.