Users of the 32-bit versions of Microsoft Office 2013 and 2016 (including the Microsoft 365 versions) are experiencing a problem where Outlook slows down or stops rendering properly, and displays white, black, or blank areas in Outlook where text and other graphical elements do not show.
Microsoft has acknowledged this issue as a memory pressure within the 32-bit Outlook process.
Install the Update to enable the Large Address Aware (LAA) for the 32-bit version of Outlook 2016 and Outlook 2013.
Read more about this update for Outlook 2016 or Outlook 2013.