A recent Microsoft Windows or Office update has resulted in the “Home Page” tab of the Outlook

Folder Properties dialog box becoming disabled (no longer visible). If you have any “Web Enabled Outlook Folders” they will stop working – including any ArcTitan Search folders 

and also SharePoint web folders.

See attached PDF regarding Web Enabled Outlook folder issues. Also there are registry key (.reg) files attached for Outlook 2010, 2013 & 2016 to attempt to fix the problem and give you the ability to reenable "Web-enabled" folder.