My Templates add-in for Outlook has disappeared

Question

I've switched back and forth and neither let me use My Templates anymore, I can't even find it when I try adding a new app but everyone else in my office has it with no issues.

Moderator note: Moved from Microsoft 365 and Office Others

Answer 1

Hi @Vvong 

Currently, there is a known issue affecting Outlook and the My Templates add-in, as described in the following Microsoft article: https://learn.microsoft.com/en-us/office/dev/add-ins/resources/resources-office-add-in-known-issues… 

At this time, it would be helpful to contact your organization’s IT administrator and ask them to open a support ticket, as recommended in the Q&A Assist guidance. For step-by-step instructions on how to create a support request in the Microsoft Admin Center, you can refer to the following resource: Get support - Microsoft 365 admin | Microsoft Learn  

As a temporary workaround, you may consider using the Signature feature in Outlook. This option allows you to insert predefined content that is similar in functionality to My Templates. For more details, please see: How to add and change an email signature in Outlook - Microsoft Support 

I hope this information provides additional clarity and helps you move forward. 

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Answer 2

The behavior matches a known Outlook service issue rather than something specific to the device or profile.

Current status and what it means:

• The My Templates add-in is currently affected by an active service-side problem in Exchange Online and Outlook.
• Symptoms include exactly what is described: the My Templates button missing from the ribbon, not appearing under All Apps / Add Apps, and attempts to add it back failing with a generic "Something went wrong" message.
• This is not caused by local configuration when others in the same organization still see the add-in; it is a backend discovery/authentication regression being worked on by engineering.

Key details from the active incident:

• The issue is tracked as a high‑severity Outlook add-ins problem where My Templates is missing and undiscoverable across Outlook desktop (classic and new), Outlook on the web, and Outlook mobile.
• Engineering has identified that a recent change to use REST authentication for the My Templates add-in caused access errors. That change has been rolled back, which reduced errors, but full remediation is still in progress.
• Related incidents (EX1183224, EX1238375, MO1243496) show that this can also affect other add-ins such as Viva Insights and Salesforce and can present as failures when trying to add apps.

What can be done now:

1. Because this is a service-side issue, there is no reliable client-side fix (reinstalling Office, switching between classic/new Outlook, or repairing profiles typically does not resolve it for affected mailboxes).
2. If an admin is involved and support requests it, they can:
   • Connect to Exchange Online PowerShell and run Get-App / Set-App for the My Templates add-in ID to confirm it is enabled, but current guidance is not to run these commands unless requested by Microsoft Support.
3. If the problem persists while others in the same tenant are not affected, the recommended next step is to open a support ticket via the Microsoft 365 admin center so engineering can check the mailbox and tenant against the active incident and confirm when remediation reaches this environment.

Until Microsoft completes the backend fix and the add-in rediscovery is fully restored, My Templates may remain unavailable for the affected mailbox even though it works for coworkers.

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References:

• My Templates are missing from Outlook
• Office Add-ins known issues
• Use add-ins in Outlook
• Retrieve a hidden Office Add-in