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Outlook VSTO Addins suddenly stopped showing/working - July 2024

Marc Maynard Alfaro 85 Reputation points
2024-07-04T10:42:36.4966667+00:00

Hi All,

We have a few Outlook VSTO add-ins that are in use in our company, and earlier today, we were still able to use them. This evening, there was a popup saying that a new version of Outlook is required (screenshot below):

Outlook - newer version3After restarting Outlook, our VSTO add-ins won't show. I can see that they are NOT disabled in the COM Add-ins settings, but the ribbon tabs, context menus, etc are all gone.

Can anybody advise what's going on? Has Microsoft stopped support of VSTO add-ins?

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Office
A suite of Microsoft productivity software that supports common business tasks, including word processing, email, presentations, and data management and analysis.
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  1. JR K Yoshikawa 566 Reputation points
    2024-07-17T17:39:33.5366667+00:00

    COM Add-ins not supported if you switch to New Outlook.

    Roll Back to Legacy (Classic) Outlook.

    https://support.microsoft.com/en-us/office/getting-started-with-the-new-outlook-for-windows-656bb8d9-5a60-49b2-a98b-ba7822bc7627

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