Office.js OUTLOOK, what would cause my plugin to be disabled in ribbon

Question

We have a side loaded plugin in Outlook, but for unknown reasons it's disabled for both Outlook on MacOS and on Windows within the ribbon. Plugin is loaded through M365 admin-center.

However --- in Outlook for Web (OWA) the plugin works as expected for the same user. What could be causing this sudden change?

In our case information management rights is not enabled.

Answer 1

Hi,

Thank you for the response. The behavior of disabled items started suddenly.
Are there GPO's you may can refer to directly (to narrow down search)?

I do not believe the item-context is of issue, as nobody else is experiencing this and is through intended flow (compose).

Also regarding:

Check "Optional Connected Experiences" Modern Outlook clients (especially New Outlook for Mac) disable Store and Admin-deployed add-ins if privacy settings are too strict. OWA is not affected by this local setting.

• For New Outlook on Mac: Go to Menu > Settings > Privacy.
• For Windows: Go to File > Office Account > Account Privacy > Manage Settings. Ensure "Turn on optional connected experiences" is checked. If it was off, enable it and restart Outlook.

I just verified it on my own Mac, the option is not checked here either - yet on my Mac it still works.

Answer 2

Hi Luc Pasmans

Thank you for reaching out to the Q&A Forum.

The discrepancy between OWA and Desktop clients usually indicates that local device restrictions or privacy settings are blocking the add-in from loading.

According to Q&A Assist, you can try to check for Group Policy (GPO) Restrictions first.

Since this is a business account, your IT organization may have applied security policies that restrict add-ins on Desktop devices, which do not apply to the browser-based OWA > Please ask your IT Administrator to verify policies are active:

For more information, you can refer: Manage add-ins in the admin center - Microsoft 365 admin | Microsoft Learn

Check "Optional Connected Experiences"

Modern Outlook clients (especially New Outlook for Mac) disable Store and Admin-deployed add-ins if privacy settings are too strict. OWA is not affected by this local setting.

• For New Outlook on Mac: Go to Menu > Settings > Privacy.
• For Windows: Go to File > Office Account > Account Privacy > Manage Settings.

Ensure "Turn on optional connected experiences" is checked. If it was off, enable it and restart Outlook.

Verify Item Context

Desktop clients are stricter than OWA regarding where an add-in can run. The button will be disabled if:

• The email is in the Junk Email folder.
• The Reading Pane is turned off (an email must be selected/previewed for the ribbon button to activate).

Clear the Local Cache

• For Mac: Close Outlook > right click to Finder > Go to folder and go to ~/Library/Containers/com.microsoft.Outlook/Data/Library/Caches > Delete the contents
• For Windows: Close Outlook> Press and hold Window +R > go to %LOCALAPPDATA%\Microsoft\Office\16.0\Wef\> Delete the contents

I hope this information proves helpful and I look forward to your response!

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Answer 3

There are several potential reasons why your plugin could be disabled in the ribbon for Outlook on MacOS and Windows, while still functioning in Outlook on the Web (OWA). Here are some common causes:

1. Group Policy Settings: If your organization has implemented Group Policy settings that disable all COM add-ins, this could prevent your plugin from being enabled in the desktop versions of Outlook. You may see a warning message indicating that the add-in is disabled by your system administrator.
2. Performance Issues: If the add-in causes performance problems, it may be automatically disabled by Outlook. This is logged in the Application Event log with specific event IDs (e.g., Event ID: 59) indicating that the add-in was disabled due to performance issues.
3. Registry Settings: The registry settings might be configured to always disable certain add-ins. If your add-in is listed in the registry under a policy that blocks it, it will not be enabled in the desktop versions.
4. Compatibility Issues: Sometimes, add-ins may not be fully compatible with certain versions of Outlook on MacOS or Windows, leading to them being disabled.
5. Updates or Changes: Recent updates to Outlook or changes in the M365 admin center settings could also affect the status of your add-in.

To troubleshoot, check the Group Policy settings, review the Application Event log for any relevant events, and ensure that the registry settings allow your add-in to be enabled. Additionally, confirm that there are no compatibility issues with the versions of Outlook being used.

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References:

• No add-ins loaded because of Group Policy settings
• Add-ins are user re-enabled after being disabled by Office programs