Who is this article for?

Users experiencing issues with application buttons not working as expected.

No special access or permissions are required.

There are a number of reasons why Mail Manager has been disabled or buttons are not enabled. These include:

• The app version of Office that is pre-installed with Windows 10 is NOT compatible with Outlook add-ins like Mail Manager.
• Outlook didn't exit correctly and disabled its Add-ins
• An add-in is repeatedly slow to load (only applies to Outlook 2013, 2016 & 2019)
• The Mail Manager Add-in is prevented from loading due to a user registry key issue (only applies to Outlook 2013, 2016, 2019 & Click-to-run installations)
• Incorrect version of the .NET Framework has been installed. Please see Minimum Hardware & Software Requirements (Pre-Requisites).

This article outlines the steps required to investigate and resolve the issue. These steps can be followed in sequence or you can jump to a specific step.

1. Reinstalling Microsoft Office 365

Windows 10 comes pre-installed with The Office app for Windows 10, which is not compatible with Outlook COM add-ins.

To resolve the issue, you will need to download and reinstall Office by signing into your Office 365 account choosing Install Office.

For further assistance, please consult your local IT team.

2. Reenabling add-ins

If Outlook was closed unexpectedly, it may have disabled the Mail Manager add-in.

To reenable the add-in:

1. Go to the File tab in Outlook.
2. Select Options from the left-hand menu.
3. Choose Add-Ins.
4. Change the Manage dropdown to Show disabled items.
5. Click Go.
6. If a Mail Manager add-in is listed, select it.
7. Click Enable.
8. Change the Manage dropdown to COM Add-ins.
9. Click Go.
10. Ensure add-in called Mail Manager Add-in is ticked.
11. Click OK.
12. Restart Outlook.

The above steps my vary based on the version of Microsoft Outlook you are using. For Outlook 2013, 2016 & 2019 please see Take control of your Outlook 2013 add-ins on the Microsoft website.

3. Checking for slow add-ins

If the issue persists, you may need to review the slow and disabled add-ins section.

To check for slow performing add-ins:

1. Open Outlook.
2. Go to the File tab.
3. Select Slow and Disabled COM Add-ins.
4. Enable the Mail Manager add-ins, setting Always enable this add-in or Do not monitor this Add-in for the next 30 days.

Please also see Outlook’s slow add-ins resiliency logic and how to always enable slow add-ins on the Microsoft website.

4. Inspecting registry

This issue may also might be caused by the Mail Manager add-in being prevented from loading due to a user registry key issue, caused by uninstalling a newer version and installed an older version of Outlook.

Use the Mail Manager Registry Checker to establish if there are any missing or incorrectly set registry keys.
An error displayed would typically look like: "Failed to initialize the Add-In" or "Error code 0x4005" being displayed to the screen.

Registry Checker is a tool developed to assist in finding missing or incorrectly set registry keys that affect Mail Manager. The tool does not make changes to the Windows registry, it only reads keys related to Mail Manager.

To use the registry checker:

1. Browse to the Mail Manager Support folder.
   By default this will be: C:\Program Files\Mail Manager\Support or %localappdata%\Mail Manager\Program Files\Support.
2. Run RegistryChecker.exe.
3. Select Check Registry.
   The output from the check will appear.
4. Review the list of actions required.

If any actions are required, contact your IT Support to make the necessary changes.

If there are no actions required to change, check to ensure the LoadBehavior Registry setting is set to a value of 3.

To check this setting:

1. Open the Windows Registry Editor.
2. Access the Edit menu.
3. Select Find....
4. Enter MailManager.Managed in the Find what text field.
5. Tick Keys in the Look section.
6. Untick Values and Data in the Look section.
7. Click Find Next
8. When a key has been found look for a value called LoadBehavior.
9. Check that the value is 3, if not double-click and change to 3

There are four possible locations this should be located, but not all four have to be found depending on installation environment:

• HKEY_CURRENT_USER\Software\Microsoft\Office\Outlook\Addins\MailManager.Managed
• HKEY_LOCAL_MACHINE\Software\Microsoft\Office\Outlook\Addins\MailManager.Managed
• HKEY_USERS\xxxxxxxxx\Software\Microsoft\Office\Outlook\Addins\MailManager.Managed
• HKEY_LOCAL_MACHINE\Software\Wow6432Node\Microsoft\Office\Outlook\Addins\MailManager.Managed

For C2R Installations:

• HKEY_LOCAL_MACHINE\Software\Microsoft\Office\15.0\ClickToRun\REGISTRY\MACHINE\Software\Wow6432Node\Microsoft\Office\Outlook\Addins\MailManager.Managed

Another registry setting that can be checked are this, where the version number, 16.0, may change depending on the version of Outlook in use:

• HKEY_Current_User\Software\Microsoft\Office\16.0\Outlook\Resiliency\DoNotDisableAddinList – Value Name MailManager.Managed Value Type – Reg_DWord Value Data 1
• HKEY_Current_User\Software\Microsoft\Office\16.0\Outlook\Resiliency\DoNotDisableAddinList – Value Name Mail.Manager Value Type – Reg_DWord Value Data 1

If your registry changes are not saving, please contact your local IT team for more assistance as you may not have the required domain permissions to action these changes.

5. Repairing Microsoft .NET Framework

The next step is to perform a repair of Microsoft .NET Framework 4.6 (or 4.0 if this is installed instead).

To repair the framework:

1. Download the Microsoft .NET Framework Repair Tool.
2. Run the Repair Tool.
3. Follow the on-screen instructions.
4. Reboot your PC.

Reopen Mail Manager and see if the issue was resolved.

6. Installing Microsoft Visual C++14.42.34433.0

One customer had an environment where installing Microsoft Visual C++14.42.34433.0 fixed this for them.

• Windows x64
• Windows x32

If the issue continues, then please contact our Support team. To assist the team in resolving the issue, please ensure to capture diagnostic information required for investigation.