There are two causes for this:
- The Virtual Cabinet Add-in needs to be removed and reinstalled to restore it.
- The Virtual Cabinet Add-in could be disabled in MS Outlook.
To remove and reinstall the Virtual Cabinet Add-In:
Close all MS Office applications: MS Outlook, MS Word, MS Excel.
Open Virtual CabinetClick on the Virtual Cabinet Settings option in top left corner.
Select Microsoft Office Addin option and then select the Remove Office Addin option.
This will remove the Virtual Cabinet Add-in from all MS Office Applications.
The Add-ins will now be installed again.
Click on the Virtual Cabinet Settings option again.
Select Microsoft Office Addin option and then select the Install Office Addin option.
The Add-ins will be installed
Open MS Outlook to confirm the Virtual Cabinet Add-in is available.
If the Virtual Cabinet Add-in is still not available, it may be disabled
in MS Outlook.
To re-enable the Add-In:
Open MS Outlook
Click on File > Options
In the Add-ins, select Disabled Items and click on GO
Check if Virtual Cabinet Office Addin for Outlook
If it is, click on the add-in and click on Enable to restore the Add-in in MS Outlook.
The Add-in should now appear in MS Outlook in the Add-ins Ribbon.