[Outlook] (debug) Clarify JS engine used when debugging event-based and spam-reporting add-ins (#5008)

* Clarify JS engine used

* Rephrase

Author: samantharamon

docs/outlook/debug-autolaunch.md

@@ -1,7 +1,7 @@
 ---
 title: Debug your event-based or spam-reporting Outlook add-in
 description: Learn how to debug your Outlook add-in that implements event-based activation or integrated spam reporting.
-ms.date: 12/19/2024
+ms.date: 01/28/2025
 ms.topic: how-to
 ms.localizationpriority: medium
 ---
@@ -165,6 +165,9 @@ After confirming that the debugger is attached, return to Outlook. In the **Debu
 
 You can now hit your breakpoints to debug your event-based activation or spam-reporting code.
 
+> [!IMPORTANT]
+> Starting in Version 2403 (Build 17425.20000), event-based and spam-reporting add-ins use the [V8 JavaScript engine](https://v8.dev/) to run JavaScript, regardless of whether debugging is turned on or off. In earlier versions, the Chakra JavaScript engine is used when debugging is off, but the V8 engine may be used when debugging is turned on.
+
 ## Stop the debugger
 
 To stop debugging the rest of the current Outlook on Windows session, in the **Debug Event-based handler** dialog, choose **Cancel**. To re-enable debugging, restart Outlook.

docs/outlook/troubleshoot-event-based-and-spam-reporting-add-ins.md

@@ -1,7 +1,7 @@
 ---
 title: Troubleshoot event-based and spam-reporting add-ins
 description: Learn how to troubleshoot development errors in Outlook add-ins that implement event-based activation or integrated spam reporting.
-ms.date: 05/20/2024
+ms.date: 01/28/2025
 ms.topic: troubleshooting
 ms.localizationpriority: medium
 ---
@@ -38,11 +38,11 @@ As you develop your [event-based](autolaunch.md) or [spam-reporting](spam-report
     Office.actions.associate("onNewMessageComposeHandler", onNewMessageComposeHandler);
     ```
 
-- The JavaScript code of event-based and spam-reporting add-ins that run in classic Outlook on Windows only supports [ECMAScript 2016](https://262.ecma-international.org/7.0/) and earlier specifications. Some examples of programming syntax to avoid are as follows.
+- In classic Outlook on Windows versions prior to Version 2403 (Build 17425.20000), the JavaScript code of event-based and spam-reporting add-ins only supports [ECMAScript 2016](https://262.ecma-international.org/7.0/) and earlier specifications. Some examples of programming syntax to avoid are as follows.
   - Avoid using `async` and `await` statements in your code. Including these in your JavaScript code will cause the add-in to time out.
   - Avoid using the [conditional (ternary) operator](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Operators/Conditional_Operator) as it will prevent your add-in from loading.
 
-  If your add-in has only one JavaScript file referenced by Outlook on the web, on Windows (new and classic), and on Mac, you must limit your code to ECMAScript 2016 to ensure that your add-in runs in classic Outlook on Windows. However, if you have a separate JavaScript file referenced by Outlook on the web, on Mac, and new Outlook on Windows, you can implement a later ECMAScript specification in that file.
+  If your add-in has only one JavaScript file referenced by Outlook on the web, on Windows (new and classic), and on Mac, you must limit your code to ECMAScript 2016 to ensure that your add-in runs in earlier versions of classic Outlook on Windows. However, if you have a separate JavaScript file referenced by Outlook on the web, on Mac, recent versions of classic Outlook on Windows, and the new Outlook on Windows, you can implement a later ECMAScript specification in that file.
 
 ## Debug your add-in