Symptoms

If you're using Outlook 2013 or 2016, you may see a message that says "A problem was detected with an add-in and it has been disabled" when you start the application. Clicking on the "View Disabled Add-ins... " button shows a form with the list of add-ins and how each one impacts Outlook performance. Sometimes, even if you put the add-in into the "Always enable this add-in" list, it is still flagged as "Inactive" even after restarting Outlook.

Another symptom is that the Outlook splash screen stops at loading add-ins, and Outlook is automatically closed after that. Alternatively, Outlook may keep on loading add-ins, but never complete the loading process.

Cause

Outlook 2013 and 2016 are less tolerant to long add-in load time compared to earlier Outlook revisions.

Resolutions

Here are some solutions to fix disabled add-ins in Outlook 2013 and 2016:

Option 1: Always Enable Add-in

A temporary solution is to click on "Always enable this add-in" when the "A problem was detected with an add-in" message appears. However, this may not always work as some add-ins may still be flagged as "Inactive" even after doing this.

Option 2: Registry Key Fix

You can create a registry key to force Outlook to never disable a particular add-in. Here are the steps to do this:

1. Open the Registry Editor
2. Go to this key, depending on your Outlook version:

3. Outlook 2013	[HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\15.0\Outlook\Resiliency\AddinList]
   Outlook 2016	[HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\16.0\Outlook\Resiliency\AddinList]

4. Create a new DWORD value with the name of the add-in (e.g., "AOP.RC.ResourceFinder.Addin") and set its value to 1.
5. Next, go to this key:

6. [HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\Outlook\Addins\AOP.RC.ResourceFinder.Addin]

7. Create a new DWORD value called "LoadBehavior" and set its value to 3.
8. Finally, go to this key:
9. Create a new DWORD value called "LoadBehavior" and set its value to 3.
10. Finally, go to this key:

11. [HKEY_LOCAL_MACHINE\Software\Microsoft\Office\Outlook\Addins\AOP.RC.ResourceFinder.Addin]

12. Create a new DWORD value called "LoadBehavior" and set its value to 3.

Option 3: Repair or Reinstall Office

If none of the above options work, you may want to try repairing or reinstalling your Office installation. This may fix any issues with add-ins or other Outlook functionality.

Conclusion

Disabled add-ins can be a frustrating issue in Outlook 2013 and 2016, but there are several solutions available. Trying these options should help you fix the problem and get your add-ins up and running again.