---
title: "📋 Outlook Add-In (classic): Prevent automatic deactivation (Registry)"
url: "https://support.ftapi.com/en/article/warum-wird-mein-outlook-add-in-automatisch-deaktiviert"
language: "en"
last_updated: "2026-06-22T07:10:19.208Z"
---

# 📋 Outlook Add-In (classic): Prevent automatic deactivation (Registry)

This article provides administrators with instructions for diagnosing and reactivating the Outlook Add-In if it is automatically disabled by Microsoft Outlook.

Microsoft Outlook can automatically disable add-ins if they increase Outlook's startup time or cause errors. In some cases, the FTAPI Outlook Add-In remains disabled even after a reinstallation. This can be caused by specific registry entries or Group Policy Objects (GPOs) that prevent the add-in from loading.

## Possible causes

-   **Outlook classifies the add-in as performance-degrading:** If the FTAPI Outlook Add-In takes too long to load, it may be added to Outlook's "ignore list".
-   **Outlook permanently disables the add-in:** A registry value may prevent the add-in from loading again.
-   **Corporate policies (GPOs) block the add-in:** A Group Policy Object (GPO) may prevent the FTAPI Outlook Add-In from loading. In this case, changes can only be made by the IT department.

## Step-by-step guide for reactivation

### 1\. Checking the Outlook Resiliency list

If the FTAPI Outlook Add-In has been classified as problematic by Outlook, it may have been saved in the so-called "Resiliency" list. Check the following registry path:

`HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Resiliency`

If there are entries related to the FTAPI Outlook Add-In, you can remove them to allow for reactivation. If you are unsure, contact your IT department before making changes to the registry.

### 2\. Checking the “LoadBehavior” value

If the FTAPI Outlook Add-In is visible in the list of installed add-ins but cannot be activated, check the following registry path:

`HKEY_CURRENT_USER\Software\Microsoft\Office\Outlook\Addins\FTAPI.AddIn\LoadBehavior`

The value should be set to **3**. If Outlook automatically resets this value to **2**, there may be an issue with the add-in configuration or the system environment. In this case, we recommend checking the Windows Event Viewer for errors or creating a support request.

### 3\. Protection against automatic deactivation (DoNotDisableAddinList)

If the FTAPI Outlook Add-In is running stably, it can be protected from automatic deactivation by Outlook. To do this, it must be added to the so-called “DoNotDisableAddinList”. This setting can be configured via the Windows Registry:

`HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Office\16.0\Outlook\Resiliency\DoNotDisableAddinList`

Create a new **DWORD** value in this path with the name of the FTAPI Outlook Add-In and set the value to **1**. This prevents Outlook from automatically disabling the add-in.

> **Note: Changes to the Windows Registry should only be made by IT administrators or experienced users. Create a backup of the registry beforehand.**

## Additional notes

-   If the problem persists, check the Windows Event Viewer under **Windows Logs > Application** for errors related to the FTAPI Outlook Add-In.
-   If the add-in is displayed as disabled in Outlook under "Manage Add-ins", you can try to reactivate it manually there.
-   If the FTAPI Outlook Add-In remains disabled despite manual activation, a Group Policy in your corporate environment could be the cause. In this case, contact your IT department to check if a corresponding policy is blocking the add-in.