Outlook 2016 for Mac - when reading pane is set to right, the column to the left that contains a list of messages will appear blank, that is, the headings for groups will be present and the list items are blank that would normally give you the message's subject, sender and message preview. This issue had occurred before on the user's Mac, where previously I had restored his view to defaults which did resolve the issue the first time, unfortunately the second time I was not so lucky.
I decided to try contribute a solution that I could not find anywhere else.