Office Add-ins known issues

Last updated 06/04/2026

This article provides information about current known issues with Office Add-ins. For more information about common error messages you might encounter, see Troubleshoot user errors with Office Add-ins or contact the add-in developer on the Details + support tab on the add-in's detail page in Microsoft Marketplace.

ISSUE: Some centrally deployed Office Add-ins may disappear or fail to load

Some customers may experience issues where centrally deployed Office Add-ins are missing, unavailable, or fail to load across Office clients. In affected cases, previously installed add-ins may no longer appear in the ribbon or add-in management experience.

STATUS

Investigating.

Engineering teams are actively investigating reports affecting multiple third-party and organization-deployed add-ins.

DETAILS

Impacted add-ins:

• SAP Analytics Cloud for Excel
• Other centrally deployed and organization-managed Office Add-ins

Affected platforms/clients:

• Excel desktop
• Excel on the web
• Additional Office clients in some environments

USER IMPACT

Users may experience one or more of the following:

• Add-ins disappearing from the ribbon
• Failure to load organization-deployed add-ins
• Errors indicating the add-in is unavailable or inaccessible
• Add-ins not appearing even though deployment remains assigned by the administrator

WORKAROUND

The following actions may help in some scenarios:

• Restart the Office application.
• Refresh admin-managed add-ins from the add-ins pane.
• Wait and retry after some time while mitigations continue to roll out.
• Verify the user has access to required Microsoft 365 and Exchange Online services.
• If your organization restricts Exchange Web Services (EWS), verify required access settings are enabled.

If the issue persists, contact Microsoft Support and include diagnostic information such as session IDs, correlation IDs, logs, or network traces where available.

START DATE

Date reported: 06/04/2026

ISSUE: Office Add-in update failures and activation issues

There's an issue affecting some customers where Office Add-ins failed to update through the Store, preventing the add-in from loading successfully. Customers may have encountered errors during the Office Add-in update process, followed by the add-in being unavailable.

STATUS

Mitigated

The underlying asset delivery issue has been addressed and failures related to missing content have decreased.

Rolling out

Updates to improve add-in delivery reliability are currently being deployed broadly.

Ongoing investigation

We are continuing to work with dependent services to address remaining issues in the store-based update experience.

WORKAROUND

While fixes are rolling out, the following actions may help resolve the issue:

• Restart the Office application.
• Wait and retry the update after some time.

These steps may allow the add-in update to complete successfully in cases where propagation or retries are required.

Recommended Actions

• Retry updating the add-in if the issue was encountered previously.
• Ensure the Office application is on a supported and up-to-date version.
• If the issue persists, collect and share diagnostic information (such as session logs or network traces) with support.

START DATE

Date reported: 04/17/2026

ISSUE: Unable to remove Office Add-Ins using the Integrated apps portal

In some cases, the Microsoft 365 administrator may see an error when attempting to remove an Office Add-in via the Integrated apps portal.

STATUS

Investigating.

WORKAROUND

To remove the add-in using the Office Add-ins advanced management UI:

1. Sign in to the Microsoft 365 admin center.
2. From the left navigation bar, select ... Show all, then select Settings > Integrated apps.
3. Near the top of the page, select Add-ins from the advanced management options.
4. Select the add-in you want to remove.
5. At the bottom of the pane, select Remove add-in.
6. When prompted to confirm, select Remove.

START DATE

Date reported: 04/20/2026

ISSUE: Missing Office Add-Ins deployed via Centralized Deployment

Following a recent service flight rollback affecting Exchange Web Services (EWS), deployment and acquisition of Office Add-ins currently depend on EWS being enabled. If this setting is turned off at either the organization or mailbox level, Office Add-ins may fail to appear or install successfully.

STATUS

Mitigated. Tracking ID: EX1255397 and EX1259460

WORKAROUND

To ensure add-ins function correctly, verify that EWS access is enabled by running the following Exchange Online PowerShell command:

Set-OrganizationConfig -EwsEnabled:$true

If EWS access is restricted through application access policies or mailbox-level configuration (for example, EwsEnabled is set to $false), these settings may prevent Office Add-ins from being shown to users.

For additional guidance on managing EWS access in Exchange Online, please refer to: Control access to EWS in Exchange.

START DATE

Date reported: 03/23/2026

ISSUE: Users can't find or restore an add-in deployed via optional deployment

When an Office Add-in is deployed using the optional deployment method, individual users can choose to remove the add-in from the ribbon, and restore it later if they want to use it again. However there is a regression where in some cases a user can't restore the add-in.

STATUS

Open; tracking ID: ICM21000000950868

IMPACT

Users are unable to restore an add-in to the ribbon after they remove it. Even if the admin chooses to redeploy the add-in to all users, it may not appear.

WORKAROUND

Create a Microsoft 365 group to implement optional deployment. This works for Integrated Apps on both XML manifest and unified manifest (JSON) Office Add-ins.

1. Create a Microsoft 365 group for a specific group of users who will use the add-in. For more information, see Create a Microsoft 365 group.
   1. Specify a group name such as "My Add-in users".
   2. On the Members page, choose the name of one or more people who will be designated as members of the group. These people will have optional access to the add-in on their ribbon and can add or remove it.
2. Go to the Microsoft 365 admin center and update the deployment for the add-in as follows.
   1. Apply to Specific users/groups. Use the name of the Microsoft 365 group you created previously.
   2. Choose the deployment type of Fixed (Default).

Once the deployment is complete, anyone in the Microsoft 365 group can remove the add-in from the ribbon by leaving the group. If they want to restore the add-in later, they join the group.

For more information about the previous deployment steps, see:

• User and group assignments
• Deploy Office Add-ins in the Microsoft 365 admin center

ISSUE: PIM-enabled tenants are unable to deploy or manage Office Add-ins via centralized deployment

When using Azure AD Privileged Identity Management (PIM) to activate admin roles, there is a regression where PIM-enabled admin roles are not correctly honored. During centralized deployment, role-based access control (RBAC) authorization fails and leads to false permission denials during add‑in deployment and management flows.

STATUS

Open; tracking id: 11126536

IMPACT

Admins are unable to deploy Office Add-ins via central deployment when using PIM-enabled admin roles.

WORKAROUND

Don't use PIM-enabled roles if you are blocked by this issue.

OUTLOOK ISSUE: Users unable to access the My Templates add-in in Exchange Online across all Outlook clients

Users report that My Templates add-in is missing and undiscoverable across all Outlook surfaces. The add-in subscription exists on affected mailboxes and Centralized Deployment returns it correctly, but client-side discovery within Outlook and Exchange services fails to surface the add-in to end users. Users cannot find it in the toolbar, ribbon, Add Apps search, All Apps, Integrated Apps in Admin Center, or via PowerShell Get-App in some cases. The issue presents as a service-side discovery or authentication regression, rather than an admin configuration or Centralized Deployment failure.

STATUS

We're currently working on a fix.

START DATE

Date reported: 01/20/2026

DETAILS

Impacted add-ins: My Templates (primary); Viva Insights (confirmed also impacted as of March 3, 2026); other default add-ins (Bing Maps, Unsubscribe, Common Actions) intermittently affected.

Severity level: High

Affected platforms/clients: Outlook Classic (Desktop, Windows), New Outlook (Desktop, Windows), Outlook on the web, Outlook mobile

USER IMPACT

Widespread, multi-tenant impact. Impact is tenant-wide in most cases.

CAUSE

Partially identified. Engineering has confirmed two contributing factors:

1. A recent backend change that switched authentication from Exchange Web Services (EWS) to REST for the My Templates add-in caused access errors. The REST auth change was rolled back on March 3, 2026. This produced a significant drop in errors, but full remediation has not been achieved. The subscription is present on the mailbox, but add-in information is not returned to clients.
2. Historical/recurring root cause: A prior wave was resolved via rollback + cache resets in December 2025 — but some tenants never fully recovered.

WORK AROUND (steps to mitigate)

No reliable universal workaround exists. The following steps have been attempted by support teams with limited/inconsistent success:

1. Global Admin PowerShell — re-enable the add-in org-wide (may take up to 72 hours to reflect; some tenants encounter 401 errors):

   
   Set-App -Identity a216ceed-7791-4635-a752-5a4ac0a5eb93 -OrganizationApp -Enabled $true
   
   

2. Verify the add-in status:

   
   Get-App -Identity a216ceed-7791-4635-a752-5a4ac0a5eb93
   
   

3. Refresh the Outlook client — In some cases, a page refresh or Outlook restart triggered the add-in to reappear temporarily.
4. Submit in-app feedback with diagnostic logs — Go to Help > Feedback > Report a Problem in Outlook and share the Session ID / User ID with support so engineering can pull diagnostics.
5. Reference the public support article — See My Templates are missing from Outlook.

NOTES TO ADMIN

Re-enabling the add-in via PowerShell or the Admin Center does not guarantee resolution while the service-side issue is active. Engineering is working on a fix and will post updates to the Service Health Dashboard (SHD).

ISSUE: Intermittent failure to load or deploy Office Add-ins due to Exchange authentication changes

Some users experience issues where Office add-ins failed to load, appeared missing, or could not be deployed through the Microsoft 365 admin center. In affected scenarios, add-ins were visible in the admin experience or store but did not render or appear correctly in Outlook or other Office clients.

START DATE

Reported by: Microsoft Support / Customer Reports on: 02/25/2026

DETAILS

Impacted add-ins: Admin-deployed and organization-scoped Office add-ins (including third‑party add-ins)

Severity level: Medium

Current status: Open, mitigation has begun rolling out.

Affected platforms/clients: Office clients, Microsoft 365 admin center (centralized deployment experience)

USER IMPACT

Intermittent authentication failures cause Office add-ins to appear missing or fail to deploy. This primarily affects tenants impacted by recent Exchange Web Services (EWS) security enforcement changes.

CAUSE

As part of ongoing Exchange Web Services (EWS) security improvements, Microsoft enforced stricter authentication requirements that no longer allow certain legacy authentication methods. Some add-in service calls were still relying on these legacy paths, causing add-in metadata retrieval requests to be rejected. As a result, affected add-ins could not be loaded or displayed correctly for users.

WORK AROUND (steps to mitigate)

No customer action was required. Microsoft applied targeted mitigations to restore compatibility while a longer-term fix is validated. Customers who continue to experience issues are advised to contact Microsoft Support for assistance.

SEE ALSO

For more information, see Deprecation of Exchange Web Services (EWS) in Exchange Online.

OUTLOOK ISSUE: Base64-encoded images become corrupted when forwarding messages from a shared mailbox with Cached Exchange Mode turned off

In classic Outlook on Windows, when Cached Exchange Mode is turned off, Base64-encoded images in a message may become corrupted when a user forwards the message from a shared mailbox.

Clients affected: Classic Outlook on Windows

STATUS

We're currently working on a fix.

START DATE

Date reported: 11/3/2025

WORKAROUND

If possible, turn on Cached Exchange Mode when sending emails with Base64-encoded images from a shared mailbox. For guidance, see Turn on Cached Exchange Mode. Alternatively, include the Base64-encoded image as a file attachment instead.

OUTLOOK ISSUE: Users may experience delays of up to ten seconds loading signature add-in images in Exchange Online

STATUS

We've determined that a recent update to an authentication component of attachment logging introduced a regression which is resulting in impact. We're reverting this update to resolve the issue.

Tracking ID: 706911563

IMPACT

Some users may experience delays of up to ten seconds loading images in Exchange Online. This section will be updated as our investigation continues.

START DATE

Monday, 11/03/2025, at 4:31 PM UTC

OUTLOOK ISSUE: Delays loading inline images in email signatures in the new Outlook for Windows and Outlook for the web

We're currently investigating reports from Outlook users who are experiencing loading delays of inline images in email signatures when using the new Outlook for Windows and Outlook for the web. Our findings indicate that this is a server-side performance issue that affects rendering of all inline images. Attempting to send messages while the images are not yet loaded results in the following dialog box.

👁 Outlook images still loading error message.

Tracking ID: 678890927

Client version: 20250822005.18

STATUS

We're still receiving isolated reports from some users regarding this previously resolved issue. While the issue has been largely mitigated, certain users in specific regions are still experiencing inline signature images loading slowly and the blocking dialog during email send. Because this stems from a server-side performance delay, the impact varies by customer and region. Those affected may see delays when loading inline images—particularly in scenarios involving signature add-ins. We're actively investigating this issue with highest priority.

WORKAROUND

Options:

1. Remove inline images from signature.
2. Wait for images to load before sending the file.
3. Switch to classic Outlook for Windows or Outlook for Mac.

ISSUE: Centrally deployed add-in error "You don't have permission to use this add-in"

Numerous customers report that after updating Office from 2505 to 2507 their add-in will not load and an error is displayed "You don't have permission to use this add-in. Contact your system administrator." Any add-in may reproduce this issue; it is not specific to a single add-in.

👁 Excel web add-in permissions error message.

Tracking ID: 667052546

Version affected: Office Monthly Enterprise 2507

STATUS

A fix is being deployed.

WORKAROUND

Option 1: Refresh admin-managed add-ins

1. Select Home > Add-ins in the ribbon.
2. Select More add-ins.
3. Go to the Admin Managed tab.
4. Select the Refresh button in top right.
5. The add-in should reappear. Open it to reload the add-in.

Option 2: Forced admin refresh

IT admins can force the add-ins to refresh by creating the following registry key.

Key: HKCU\Software\Microsoft\Office\16.0\WEF\TrustedCatalogs\ClearInstalledExtensions Value: DWORD = 1

EXCEL ISSUE: Increased frequency of RichApi.Error: Error code: 0xF5320001

Since late August, customers are seeing an increase in RichApi.Error 0xF532001 in their error telemetry. This error happens only when the Office.ribbon.requestUpdate API is called immediately after the Office.ribbon.requestCreateControls API is called.

Tracking ID: 10529994

GitHub issue: Increased frequency of RichApi.Error code 0xF5320001

STATUS

We're currently working on a fix.

START DATE

Reports began late August 2025. Date opened: 09/04/2025

WORKAROUND

Options:

1. When you make the initial requestCreateControls call, include the enabled/disabled state, if known. Instead of making two calls one right after the other, do it in one call.
2. Roll back Office from version 2508 to 2507.

RESOLVED: Classic Outlook on Windows: Installed add-ins are missing

Some users were unable to find their installed add-ins in classic Outlook on Windows.

Impacted versions: Version 2603 (Build 19822.20114) and later

STATUS

Resolved. Affected users must restart their Outlook client to load their add-ins. Multiple restarts may be needed.

Tracking IDs: 784225604, 781077848

START DATE

Date reported: Tuesday, 04/14/2026

RESOLUTION DATE

Date fixed: Wednesday, 04/22/2026

RESOLVED: Microsoft Marketplace: Issues installing add-ins from the Marketplace

Some users may experienced failures when installing add-ins from the Microsoft Marketplace. During the installation flow, the process may not complete successfully, and users may see a 50x server-related error.

STATUS

The issue is now resolved.

START TIME

Sunday, 02/08/2026

RESOLUTION TIME

Friday, 02/13/2026

RESOLVED: Outlook for Mac: Signatures not inserted using add-ins and user with Smart Alerts add-ins not able to send email

A disruption in processing LaunchEvent caused the following issues:

• Signatures were not stamped on outgoing emails.
• Users with Smart Alerts add-ins were unable to send emails in some cases.

STATUS

Resolved. This issue was caused by a temporary configuration issue during a backend change management update for event-based activation support. For a subset of users having event-based add-ins, this resulted in add‑ins not initializing as expected, which in turn blocked sending emails. The configuration has now been corrected.

Note: Because these settings are cached locally and sync asynchronously, some users may need to restart Outlook more than once to pick up the updated configuration.

Tracking ID: 734492427

START TIME

Thursday, 01/15/2026 5:45am PST

RESOLUTION TIME

The fix was released Thursday, 01/15/2026 7:00am PST

RESOLVED: EXCEL: RichApi.Error code 0x8002802B known as hrNotFound is occurring more frequently when not expected

Users experienced failures when executing Excel grid operations initiated through add-in commands on the ribbon or context menu. This issue occured primarily when users have Custom Functions.

Platform affected: Windows Desktop

STATUS

Users should upgrade Excel to 2508 (19127.20264) or later for the fix.

START DATE

Date reported: SEP 17, 2025

RESOLUTION DATE

Date fixed: 09/26/2025

SEE ALSO

Fixes or workaround for recent issues in classic Outlook for Windows Office-js resolved issues in GitHub Deprecation of Exchange Web Services (EWS) in Exchange Online