added note

Author: Mikejo5000

docs/debugger/how-to-test-and-debug-a-visualizer.md

@@ -1,7 +1,7 @@
 ---
 title: Test and Debug a Visualizer
 description: Test and debug a visualizer by running it from a test driver (visualizer development host) or by installing in Visual Studio and calling it from a debugger window.
-ms.date: 07/02/2021
+ms.date: 06/26/2025
 ms.topic: how-to
 dev_langs: 
   - CSharp
@@ -19,6 +19,9 @@ ms.subservice: debug-diagnostics
 ---
 # Test and Debug a Visualizer
 
+> [!IMPORTANT]
+> Starting with Visual Studio 2022 version 17.9, visualizers can now be written in .NET 6.0+ that run out-of-process using the new VisualStudio.Extensibility model. For extensions created using the new model, see the documentation at [Create Visual Studio debugger visualizers](../extensibility/visualstudio.extensibility/debugger-visualizer/debugger-visualizers.md) instead. If you need to support older versions of Visual Studio or want to ship your custom visualizers as part of a library DLL, then use the information in this article, which applies only to the older model of extension development (VSSDK).
+
 Once you have written a visualizer, you need to debug and test it.
 
 One way to test a visualizer is by installing it in Visual Studio and calling it from a debugger window. (See [How to: Install a Visualizer](../debugger/how-to-install-a-visualizer.md).) If you do that, you will need to use a second instance of Visual Studio to attach and debug the visualizer, which is running in the first instance of the debugger.