If after repairing the installation, you're still experiencing problems, then it could be something wrong with the Outlook data files.
Outlook 2016 uses two types of data files, including the Offline Outlook File (.ost) and the Outlook Data File (.pst), depending on the type of account you configured to store offline copies of your emails, contacts, calendars, and other items. If these files stop working for any reason, you can use the Office Inbox Repair Tool to scan and repair the files to get Outlook working again.