# Debugging extensions in Visual Studio

To debug an extension in Visual Studio, script debugging has to be enabled in Internet Options. Proceed as follows:

1. Open the Control Panel.

2. Select Network and Internet>Internet Options.

3. In the Internet Options dialog, select the Advanced tab.

4. Make sure that the Disable script debugging (Other) box is deselected.

   ![Internet Options dialog with Disable Script Debugging (Other) disabled](https://help.qlik.com/en-US/qlikview-developer/September2025/Subsystems/QlikViewWorkBench/Content/Resources/Images/DisableScriptDebugging.png)

5. To make the execution of the extension break, add the statement debugger; anywhere in the JavaScript code. For example, the following causes Visual Studio to prompt for how to debug:

   ```
   Qv.AddExtension('QlikView/Examples/HtmlText', function() {
   	debugger;
   	<normal_extension_code>
   });
   ```

6. If Visual Studio is used for developing an extension, select to debug in that instance of Visual Studio, otherwise select a new instance.

   ![Visual Studio Just-In-Time Debugger popup with selection of debugging applications](https://help.qlik.com/en-US/qlikview-developer/September2025/Subsystems/QlikViewWorkBench/Content/Resources/Images/JITdebugger.png)