This browser is no longer supported.
Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(51.2, 21%, 14%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EKY%3C/text%3E%3C/svg%3E)
Hi,
Using office.js, we have developed Outlook-Addin for our users to use.
In the following environments, the Outlook client app displays this error and cannot install the Add-in.
"Sorry, we Couldn't Load the add-in. Internet Explorer Disabled"
・Windows10
・Office2019
・Microsoft Office Professional Plus 2019
・Ver1808 (build 10392.20029)
・IE is not installed
Some Mac and other Windows environments can be installed without the same error.
Therefore,
・Some versions of Outlook require IE in some cases
・In some cases, depending on the version of Office.js, IE is required
I'm thinking it might be something, but I'd like to know if anyone knows what it is.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(121.6, 11%, 21%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ECM%3C/text%3E%3C/svg%3E)
Hi @Keita Yamashiro '
Welcome to our forum!
As i know, some combinations of platforms and Office versions, including perpetual versions through Office 2019, still use the webview control that comes with Internet Explorer 11 to host add-ins. More information: Support Internet Explorer 11.
Hope to help you!
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.
Thank you for your response.
Just one more question, I have confirmed that it works on devices with IE removed.
In this case, are you not using Internet Explorer Webview? Or is Internet Explorer Webview present within the Outlook client app?
Hi @Keita Yamashiro ,
Thanks for your reply!
Do you mean that how does it work without using IE?
If so, Office Add-ins are web applications that are displayed inside IFrames when running on Office on the web. Office Add-ins are displayed using embedded browser controls when running in Office on Windows or Office on the Mac. The embedded browser controls are supplied by the operating system or by a browser installed on the user's computer.
Thank you for your response.
Do you mean that how does it work without using IE?
It means that you have uninstalled IE.
・In Windows, uninstall IE
・On Mac, remove IE from applications
I checked the above and it worked on some devices.
displayed using embedded browser controls
Does it work if I have other browsers installed, e.g. Safari or Firefox?
Hi @Keita Yamashiro ,
Thanks for your quick response and sorry for my misunderstanding！
Does it work if I have other browsers installed, e.g. Safari or Firefox?
For Non-Windows platforms:
For Perpetual versions of Office on Windows:
More information: Browsers used by Office Add-ins.
Thanks.
I couldn't find this info so I asked in the forum.
But thanks to you I finally understand it.
Hi @Keita Yamashiro ,
Glad to help you!