Outlook add-in deployed via Integrated Apps not appearing for assigned users

Question

Hello,

I developed an Outlook add-in and deployed it using the manifest XML through the Microsoft 365 admin center (https://admin.microsoft.com/#/Settings/IntegratedApps). I assigned the add-in only to a few test users.

Issue: Even after more than a week, none of the assigned users can see the add-in in either Outlook on the web or the new Outlook desktop app.

Observations:

• The add-in is only visible if a user manually sideloads the manifest themselves using https://aka.ms/olksideload And it works fine.
• Deployment through Integrated Apps shows as successful in the admin center.

Permissions and assignments appear correct.

Question:

Is there a known delay or additional step required for add-ins deployed via Integrated Apps to appear in Outlook?

Are there specific prerequisites (e.g., licensing, Outlook client version, or policy settings) that could prevent the add-in from showing up?

How can I troubleshoot why the add-in is not appearing for assigned users?

Thank you in advance for your guidance.

Answer 1

Hello,

We have reintroduced the same application with a different app ID in the manifest file for the same set of users. This time, rather than providing the manifest link, we opted to upload the manifest file directly. Consequently, there should now be two applications available. We considered waiting for 24 to 72 hours again for the second application to appear.

However, after a few hours, we contacted 365 support, and they advised us to deploy the first application across the entire organization. Following this, both applications began to appear for the specific users we had included.

We were unable to determine a root cause or a solution for this issue, as it resolved itself. Uploading the manifest file might be a potential solution.

Answer 2

Hi Himesh

Based on your description, I found a Knowledge Base article that seems to relate to your situation. You can review this documentation Office Add-ins known issues - Office Add-ins | Microsoft Learn, which also includes workaround solutions.

I hope this helps, and please let me know if you have any additional questions!

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Answer 3

There are no extra manual steps after deploying an Outlook add-in via Integrated Apps, but several prerequisites and known behaviors can prevent it from appearing for users.

Key points and prerequisites

1. Propagation delay
   • After centralized deployment, it can take up to 24 hours for an add-in to appear on all users’ clients.
   • In this case the delay is already more than a week, so normal propagation delay is not the cause.
2. Centralized deployment / Integrated Apps behavior
   • Centralized deployment (including via Integrated Apps) is the recommended way to deploy Office Add-ins to users and groups.
   • When the relevant Office app starts, the add-in is automatically downloaded and, if it supports add-in commands, appears in the ribbon.
   • Add-ins stop appearing if the admin turns them off/deletes them, or if the user is removed from the assigned group or from Microsoft Entra ID.
3. Where users should see the add-in
   • For Outlook, users should check Home → Get more add-ins (Store) → Admin-managed.
   • If the add-in is not pinned to the ribbon, it may still be available under Admin-managed.
4. Assignment model
   • Admins can assign add-ins to Everyone or to specific users/groups. If specific users/groups are used, ensure:
     • The test users are directly assigned or in a top-level group.
     • Centralized deployment does not support nested group assignments or groups that have parent groups. Users in nested groups will not see the add-in.
5. Outlook client/platform support
   • Centralized deployment supports Office on Windows, Mac, and Office for the web. For Outlook Mobile add-ins, it also supports iOS and Android.
   • Ensure the Outlook clients in use are within the supported platforms for centralized deployment.
6. Known service-side issues
   • There is a known issue where missing Office Add-ins deployed via Centralized Deployment can occur if Exchange Web Services (EWS) is disabled. In that case, add-ins may fail to appear or install.
   • Workaround: verify that EWS is enabled in Exchange Online by running:

          Set-OrganizationConfig -EwsEnabled:$true
     

     If EWS is disabled at the organization or mailbox level, or restricted via application access policies, add-ins may not show for users.
   • There is also a separate known issue where intermittent authentication failures related to EWS security changes can cause add-ins to appear missing or fail to deploy. Mitigation is being rolled out; if symptoms match (add-ins visible in admin experience but not rendering in Outlook), contacting Microsoft Support is recommended.
7. User- and org-level requirements
   • Use the Centralized Deployment Compatibility Checker to verify that:
     • Users have valid Microsoft 365 licenses.
     • Users are correctly set up in Exchange and are ready for centralized deployment.
   • Confirm Microsoft 365 and Exchange Online requirements for centralized deployment are met for the affected users.
8. Basic troubleshooting steps for “not appearing” For the affected test users:
   1. Verify the add-in is deployed and assigned correctly
      • In the Microsoft 365 admin center, confirm the add-in is deployed via Integrated Apps and that the assignment scope includes the affected users (directly or via non-nested groups).
   2. Check in Outlook clients
      • Outlook on the web: open Outlook, go to Get more add-ins / Store → Admin-managed and see if the add-in appears.
      • New Outlook desktop: similarly, check the add-ins store/Admin-managed section.
      • If the add-in supports commands, check the Home ribbon for its button.
   3. Check for nested group usage
      • If assignment is via groups, ensure affected users are not only members of nested groups. Move them into a top-level group or assign them directly and test again.
   4. Validate EWS configuration
      • In Exchange Online PowerShell, confirm EwsEnabled is not set to $false at the organization or mailbox level and that no EWS application access policies are blocking add-in scenarios.
   5. Confirm installation on the client (for desktop Outlook)
      • On Windows, check %LOCALAPPDATA%\Microsoft\Office\16.0\Wef\ for the add-in’s GUID from the manifest to see if it has been downloaded.
   6. Use the Compatibility Checker
      • Run the Centralized Deployment Compatibility Checker and review the status report for the affected users.
   7. Service health and support
      • If all requirements are met, EWS is enabled, users are correctly assigned, and the add-in still does not appear (while sideloading works), this aligns with the known EWS-related issues. In that case, open a support ticket via the Microsoft 365 admin center so engineering can review tenant-level logs.

There is no special “extra step” after deployment via Integrated Apps beyond ensuring centralized deployment requirements are met, EWS is enabled and not blocked, users are assigned via supported group models (no nested groups), and allowing for propagation time. Persistent absence beyond these checks should be escalated to Microsoft Support, especially in light of the documented EWS-related issues.

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References:

• Deploy Office Add-ins in the Microsoft 365 admin center
• Office Add-ins known issues
• Users don't see add-ins
• Determine if centralized deployment of Office Add-ins works for your organization
• Centralized deployment FAQ