Installed add-in is not visible in Microsoft Outlook

Problem:

Upon installation, an installed Outlook add-in is not visible in Microsoft Outlook.

 

Solution:

You need to delete extend.dat file from the user's profile and check whether the add-in is not listed among the disabled items.

Remove extend.dat

If you are using Microsoft Outlook 2010 or 2013, skip this part and go straight to Check the Disabled Items.

To remove extend.dat, follow these steps:

1. Exit Outlook.
2. In Windows Explorer choose Tools, Folder Options, View tab and select Show hidden files and folders.

3. Go to folder

   C:\Document and Settings\<user>\Local settings\Application data\Microsoft\Outlook

   where <user> is the name of the user's system in which the problem occurs.

4. Find extend.dat in this folder and delete it.
5. Restart Outlook.

Check the Disabled Items

To check whether the add-in is listed in the disabled items, i.e. add-in is disabled in Outlook, proceed as follows.

For Microsoft Outlook 2003:

1. Choose from the top menu Help, and About Microsoft Office Outlook.
2. Click Disabled Items.
3. If the add-in is included in the list, choose it and click Enable.
4. Restart Outlook.

For Microsoft Outlook 2007:

1. Choose from the top menu Tools, Trust Center and click Add-ins tab.
2. From the Manage dropdown menu, choose Disabled Items and click Go.
3. If the add-in is included in the list, choose it and click Enable.
4. Restart Outlook.

For Microsoft Outlook 2010 and 2013:

1. Choose from the top menu File, Options and click Add-Ins tab.
2. From the Manage dropdown menu, choose Disabled Items and click Go.
3. If the add-in is included in the list, choose it and click Enable.
4. Restart Outlook.