Feature_browser_emulation Edge
- While the proposed “solution” to add dword:00002ee1 to FEATUREBROWSEREMULATION causes the webbrowser to (falsely) report Edge/12.9200AGENT as USERAGENT, in fact it still uses the Trident engine to render the web content.
- Clear FEATUREBROWSEREMULATION registry setting to default, corresponding application specific registry key will be deleted. Prefer IE7 Standards mode, default value for the control. Prefer IE8 mode, default value for Internet Explorer 8.
Office Add-ins are web applications that are displayed using iFrames when running in Office on the web and using embedded browser controls in Office for desktop and mobile clients. Add-ins also need a JavaScript engine to run the JavaScript. Both the embedded browser and the engine are supplied by a browser installed on the user's computer.
Which browser is used depends on:
This package is now obsolete and contains no DLLs. Please use Microsoft.Toolkit.Wpf.UI.Controls.WebView or Microsoft.Toolkit.Forms.UI.Controls.WebView packages instead. FEATUREBROWSEREMULATION is a setting that controls which Internet Explorer version certain browser controls should mimic. Although popular with browser hijackers and other adware, it is not a risk by itself.
- The computer's operating system.
- Whether the add-in is running in Office on the web, Microsoft 365, or non-subscription Office 2013 or later.
The following table shows which browser is used for the various platforms and operating systems.
| OS | Office version | Edge WebView2 (Chromium-based) installed? | Browser |
|---|---|---|---|
| any | Office on the web | Not applicable | The browser in which Office is opened. |
| Mac | any | Not applicable | Safari |
| iOS | any | Not applicable | Safari |
| Android | any | Not applicable | Chrome |
| Windows 7, 8.1, 10 | non-subscription Office 2013 or later | Doesn't matter | Internet Explorer 11 |
| Windows 7 | Microsoft 365 | Doesn't matter | Internet Explorer 11 |
| Windows 8.1, Windows 10 ver. < 1903 | Microsoft 365 | No | Internet Explorer 11 |
| Windows 10 ver. >= 1903 | Microsoft 365 ver. < 16.0.116291 | Doesn't matter | Internet Explorer 11 |
| Windows 10 ver. >= 1903 | Microsoft 365 ver. >= 16.0.11629 AND < 16.0.13530.204241 | Doesn't matter | Microsoft Edge2, 3 with original WebView (EdgeHTML) |
| Windows 10 ver. >= 1903 | Microsoft 365 ver. >= 16.0.13530.204241 | No | Microsoft Edge2, 3 with original WebView (EdgeHTML) |
| Windows 8.1 Windows 10 | Microsoft 365 ver. >= 16.0.13530.204241 | Yes4 | Microsoft Edge2 with WebView2 (Chromium-based) |
1 See the update history page and how to find your Office client version and update channel for more details.
2 When Microsoft Edge is being used, the Windows 10 Narrator (sometimes called a 'screen reader') reads the <title> tag in the page that opens in the task pane. When Internet Explorer 11 is being used, the Narrator reads the title bar of the task pane, which comes from the <DisplayName> value in the add-in's manifest.
3 If your add-in includes the <Runtimes> element in the manifest, then it will not use Microsoft Edge with the original WebView (EdgeHTML). If the conditions for using Microsoft Edge with WebView2 (Chromium-based) are met, then the add-in uses that browser. Otherwise, it uses Internet Explorer 11 regardless of the Windows or Microsoft 365 version. For more information, see Runtimes.
4 The embeddable WebView2 control must be installed in addition to the installation of Microsoft Edge so that Office can embed it. To install it, see Microsoft Edge WebView2 / Embed web content ... with Microsoft Edge WebView2.
Important
Internet Explorer 11 does not support JavaScript versions later than ES5. If any of your add-in's users have platforms that use Internet Explorer 11, then to use the syntax and features of ECMAScript 2015 or later, you have two options:
- Write your code in ECMAScript 2015 (also called ES6) or later JavaScript, or in TypeScript, and then compile your code to ES5 JavaScript using a compiler such as babel or tsc.
- Write in ECMAScript 2015 or later JavaScript, but also load a polyfill library such as core-js that enables IE to run your code.
Also, Internet Explorer 11 does not support some HTML5 features such as media, recording, and location.
Troubleshooting Microsoft Edge issues
Service Workers are not working
Office Add-ins do not support Service Workers when the original Microsoft Edge WebView, EdgeHTML, is used. They are supported with the Chromium-based Edge WebView2.
Scroll bar does not appear in task pane
By default, scroll bars in Microsoft Edge are hidden until hovered over. To ensure that the scroll bar is always visible, the CSS styling that applies to the <body> element of the pages in the task pane should include the -ms-overflow-style property and it should be set to scrollbar.
When debugging with the Microsoft Edge DevTools, the add-in crashes or reloads
Setting breakpoints in the Microsoft Edge DevTools can cause Office to think that the add-in is hung. It will automatically reload the add-in when this happens. To prevent this, add the following Registry key and value to the development computer: [HKEY_LOCAL_MACHINESOFTWAREMicrosoftOffice16.0Wef]'AlertInterval'=dword:00000000.
When the add-in tries to open, get 'ADD-IN ERROR We can't open this add-in from the localhost' error
Feature_browser_emulation Ie6
One known cause is that Microsoft Edge requires that localhost be given a loopback exemption on the development computer. Follow the instructions at Cannot open add-in from localhost.
Get errors trying to download a PDF file
Directly downloading blobs as PDF files in an add-in is not supported when Edge is the browser. The workaround is to create a simple web application that downloads blobs as PDF files. In your add-in, call the Office.context.ui.openBrowserWindow(url) method and pass the URL of the web application. This will open the web application in a browser window outside of Office.
See also
| Summary | This document describes various mitigation techniques and configurations to get the best rendering in Internet Explorer. It is especially powerful when embedded in Adobe Campaign Console. The main idea is to avoid IE rendering in compatibility mode (IE 7 look). |
| Digital Marketing Solution(s) | Adobe Campaign v6.1 from build 8021 Adobe Campaign v6.11 Adobe Campaign v7 |
| Audience | Technical administrators |
In the past (6.1 build < 8021), the server never explicitly sent user agent compatibility mode headers (X-UA-Compatible) to the web clients. Some pages contained the following meta tag but it did not always work due to tedious IE heuristics, mostly using the console.
The following HTTP header is now set by default on all requests responded by Tomcat.
This header effectively makes the console and IE render using the latest available algorithms. The update has solved all reported compatibility issues.
If this new behavior is not wanted, administrators can change the web server configuration as follows:
- To restore the old behavior (no X-UA-Compatible header set by the server), edit /tomcat-7/conf/web.xml of the instance, and add the following lines:
- To set a different value, also add the lines, but set the desired value inside the added element.
- To restore the default new behavior (X-UA-Compatible: IE=Edge), ensure that this block is not present
Edge Browser Emulation
Note:
In any event, if you feel the need to perform such changes on any instance, contact the R&D department. It can have complex impacts on all IE clients.
It does not work for delivery previews, since they are not delivered over HTTP by the Adobe Campaign server. It is an embedded IE control into which contains the customized HTML. The http X-UA-Compatible header does not apply, and the embedded IE forces compatibility mode.
For those cases, there are the following work-arounds:
- Add the following meta tag in your delivery's <HEAD> nodes. You can also use IE=8 depending on your version.
- Another option is to create a registry key on all workstations running the console: