---
title: "Unknown server tag “ajaxToolkit:HtmlEditorExtender”"  
description: "Unknown server tag “ajaxToolkit:HtmlEditorExtender”"  
author: "Anonymous User"  
published: 2014-11-20  
updated: 2014-11-20  
canonical: https://www.mindstick.com/forum/12662/unknown-server-tag-ajaxtoolkit-htmleditorextender  
category: "asp.net"  
tags: ["asp.net", "ajax"]  
reading_time: 1 minute  

---

# Unknown server tag “ajaxToolkit:HtmlEditorExtender”

I am using ajaxcontrols and in that all [controls](https://www.mindstick.com/articles/66/how-to-create-controls-at-run-time-in-csharp-dot-net) are working well But I had not found any of the [control](https://www.mindstick.com/blog/197/asp-dot-net-repeater-control) [named as](https://answers.mindstick.com/qa/62213/name-the-cricketer-who-was-named-as-the-player-of-the-tournament-in-cricket-world-cup-2019) HtmlEditorExtender so I had just copied this tag in .html [page](https://www.mindstick.com/articles/13031/why-to-make-a-wikipedia-page)

```
<%@ Register TagPrefix="ajaxToolkit" Namespace="AjaxControlToolkit" Assembly="AjaxControlToolkit"%><ajaxToolkit:ToolkitScriptManager ID="ToolkitScriptManager1" runat="Server" /><ajaxToolkit:HtmlEditorExtender TargetControlID="txtComments" runat="server" /><asp:TextBox ID="txtComments" runat="server"></asp:TextBox>
```

here is [working fine](https://answers.mindstick.com/qa/95550/why-is-the-safari-browser-not-working-fine) but the [problem](https://yourviews.mindstick.com/view/81399/tackling-the-problem-of-unemployment-during-corona-pandemic) arises on , then i downloaded Nuget.tool on [reading](https://www.mindstick.com/articles/126273/books-commonly-found-on-college-reading-lists) some of the problems facing just like me but still its not working

what shall I do?

**My [Web.config](https://www.mindstick.com/forum/183/web-config-file) [file](https://www.mindstick.com/articles/59/encrypting-and-decrypting-files-using-c-sharp) is**

```
  <configuration><system.web><compilation debug="true" targetFramework="4.0"/><pages>  <controls>    <add tagPrefix="ajaxToolkit" assembly="AjaxControlToolkit" namespace="AjaxControlToolkit" />  </controls>  <sanitizer defaultProvider="AntiXssSanitizerProvider">    <providers>      <add name="AntiXssSanitizerProvider" type="AjaxControlToolkit.Sanitizer.HtmlAgilityPackSanitizerProvider" />    </providers>  </sanitizer></pages></system.web></configuration>
```

## Replies

### Reply by Sumit Kesarwani

Hi Tanuj, \

```
add <ajaxToolkit:ToolkitScriptManager ID="ToolkitScriptManager1" runat="Server" />     <%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit.HTMLEditor"TagPrefix="HTMLEditor" %>
```

add folowing tag in your web.config

```
<configuration><system.web><compilation debug="true" targetFramework="4.0" /><pages>  <controls>    <add tagPrefix="ajaxToolkit" assembly="AjaxControlToolkit" namespace="AjaxControlToolkit" />  </controls></pages>
```

and in page

```
<ajaxToolkit:HtmlEditorExtender ID="replyBody_HtmlEditorExtender" runat="server" Enabled="True" OnImageUploadComplete="saveFile"  ClientIDMode="AutoID" EnableSanitization="true"  TargetControlID="replyBody">
```


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Original Source: https://www.mindstick.com/forum/12662/unknown-server-tag-ajaxtoolkit-htmleditorextender

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